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The “Picture” behind Intention: What Lies at the Center of Perception

Some Considerations of Objecf-Object Oriented Philosophy

Recent engagement with Graham Harman’s “Object-Oriented Philosophy” as it stems from Brentano and Husserl, stirs in me a terrible disagreement (I use “terrible” in the Greek sense). It comes from the “picture” that for me lies behind phenomenological preoccupations with the object, and I think also is core to Heidegger’s, at least rhetorical, notion of hiddenness (dear Sophocles, your Aias  meditation on Time!)…this is the intensely visual metaphor for how the mind works, and thus how we are to orient ourselves philosophically towards the imagined “object”, philosophically equated with Being. The entire heritage in my view suffers from this essentialized orientation to the object, the thing that reveals itself only in part.

In a soon to be published text Graham Harman quotes to some effect Husserl’s object orientation in Logical Investigations:

“every intention is either an objectifying act or has its basis in such an act.” 

“whether I look at this book from above or below, from inside or outside, I always see this book. It is always one and the same thing, and that not merely in some purely physical sense [which plays no role in Husserl’s philosophy- g.h.], but in the view of our percepts themselves. If individual properties dominate variably at each step, the thing itself, as a perceived unity, is not in essence set up by some over-reaching act, founded upon these separate percepts.”

As I have argued elsewhere (linked far below), and found in my research into Spinoza’s optical theories and practices, this modern conception of a picture of consciousness as somehow oriented towards the object, in a sense, being composed by its object, is something that has its modern origin in optical metaphors drawn from the rise of dioptics, the science of the lensed refaction of rays. The transition from the Perspectivist tradition which matched linear rays from points on an object to points in the back of the eye, to the philosophical meditation on what it takes to have “clear and distinct” ideas (Descartes), led us to understand consciousness itself as oriented towards a central clarity, a clarity which, however obscure the borders, as the object of the mind composes a kind of “truth”. Under such a view it is the very nature of consciousness to be somehow defined by this centrality, this clear picture, and the obscure boundary spaces do nothing more than “serve” this center (Kepler, Descartes).

The “Clear and Distinct” Center

As just suggested, Descartes is responsible for bringing to the fore this notion of consciousness through a pursuit of the “clear and distinct” idea. It is important to note that this phrasing comes directly from dioptrics where it carried a specific meaning. In an age wherein refraction was barely understood (the law had just been identified), the quality of glass incredibly fogged and bubble-ridden, and methods of glass grinding unsettled and under continual invention, an image in a lens that was “clear” (clare) was one which was bright, and one that was “distinct” was one which, if bright enough and the properties of the glass and curve optimal, all the parts could be made out. A bright idea was one that struck one with obviousness, a distinct one one that struck with detail, that is, as being sufficiently differentiated. When looking through a microscope a “clear and distinct” image was a good image. In keeping with his preoccupations with the future science of the dioptrics of microscopes and telescopes, Descartes felt that mentally the “clear and distinct” idea was the focus of mental perception, just as the clear and distinct image is the focus of visual perception. Emotions and sensations were indistinct quite often. A pain might be very “bright” (obvious) but indistinct as to its cause or nature.  

 

In my studies I find, following Graham Burnett’s inspiration, that Descartes’ hyperbolic lens, designed as it was to bring a central object into view as clearly and distinctly as possible, was related to his hyperbolic doubt, which was meant to help focus the mind on the most bright and disguishable ideas. In both Descartes hyperbolic lens and imagination, it is the visual center of consciousness which stabilizes truth. It is the object of one’s eye and mind. I argue that Spinoza’s objection to the efficacy of Descartes’ optical hyperbolic lens contains also an objection to the notion of a central clarity, a clarity that works to anchor the mind to truth.

The Dissonance Hole

Now back to the inheritors of a concept of consciousness which finds at is center an (object) clarity. These are the phenomenological sons of Descartes’s preoccupations with the optical metaphor. To this inheritance I would like to raise a deeper question than simply exposing a central metaphor (and its possible contingent relationship of the validity of arguments that depend on it: chose another metaphor, like for instance how Plotinus uses sound, and possibly end up with different conclusions). I want to suggest that if one attends to consciousness itself, and looks to the very center of consciousness, one doesn’t find a stability there at all. In fact, there is hole at the center of vision.

Richard Sennett’s recent, and thought-provoking The Craftsman  includes the importance of this “hole”:

The capacity to localize names the power to specify where something important is happening…Localizing can result from sensory stimulation, when in a dissection a scalpel unexpected hard matter; at this moment the anatomist’s hand movements become slower and smaller. Localization can also occur when the sensory stimulation is of something missing, absent or ambiguous. An abscess in the body, sending the physical signal of a loss of tension, will localize the hand movement…

In cognitive studies, localizing is sometimes called “focal attention.” Gregory Bateson and Leon Festinger suppose that human beings focus on the difficulties and contradictions they call “cognitive dissonances.” Wittgenstein’s obsession with the precise height of a celing in one room of his house [citing that the philosopher had a ceiling lowered 3 centimeters in a house he had designed just the construction was being completed] derives from what he perceivedj as a cognitive dissonance in his rules of proportion. Localization can also occur when something works successfully. Once Frank Gehry could make titanium quilting work [citing the design of a material of specific relfective and textural capacities], he became more focused on the possibilities of the material. These complicated experiences of cognitive dissonance trace directly, as Festinger has argued, from animal behavior; the behavior consists in an animal’s capacity to attend to “here” or “this.” Parallel processing in the brain activates different neural circuits to establish the attention. In human beings, particularly in people practicing a craft, this animal thinking locates specifically where a material, a practice, or a problem matters.

Pay attention to the dissonance that lies at the center of one’s attention. As the eye plays over the surface of an object, the gaze is not upon the “object” but at the living line which erupts out of the sense of it.  If we take up Husserl’s book, we don’t even have to look at its inside, outside and bottom. We merely need to look at its cover. The eye flits across it, an electric line that traces out the variations of its color, its choice of title typeface, its wear on a corner, its color that reminds us of a dress we saw. Yes, we are “seeing” the book, but it is an eruptive book. These are not accidents to the essence of the book, but rather are produts of our engagment with it. But more than this, the “book” is not a center of our consciousness, it is is not the “object” of our consciousness, or even intentionality. In fact there is no object at all which is the focus of our altering gaze. But it goes further than even this, for if the living line does erupt from the book, we understand that the book itself is present to us as a ground of sense for which this line depends. It is not that the book is somehow constructed out of these in some “over-reaching act” but rather that the book already serves as a ground, an under-reaching ground. The dissonance of our awareness depends upon an awareness of consonance. And this consonance is not though made up of the object of the book either, for the book is perceived as a book against (or in coherence with)  a vast array of other boundary perceptions and beliefs (I see that it is a book because that is a table, and I am in a room, and “I believe that writing exists, that there are authors” etc.). Not only is the “object” not at the center of our gaze, but neither is it the whole of the sense from which we do derive our center. Our awareness is a breadth. We say that we are “looking at the book” or “thinking of the book” as a kind of short hand for mutitudnal effects which are only understood as layers or degrees. And we also “picture” (retroactively) a stability of what we are looking at, paying less attention to what it is that we are attending to (a living line of dissonance, and a counter-boundary of outer sense) .

Intentional and Other Objects

When “object-orientation” concepts of Being flow from this notion of central apparition (and also for Heideggerians necessary hiddenness), the full sense of what the mind does, what consciousness is, I think gets lost. I have not read Graham Harman extensively (only an unpublished essay, a lecture listened to, and some informative comments), but I cannot help but have the sense that there is something of a central clarity conception of consciousness that he has taken from the sons of Descartes. What is interesting to me though is that tool orientation, a craft understanding of consciousness, actually is what calls our attention to the very hole at the center of vision. A craftsman is the one that focuses on the eruptive amid an organized sense, plan or workability.

So when we consider what Graham Harman takes to be the “object” of philosophy…

1. Intentional objects (such as phenomenal trees) exist in uneasy alliance with their accidents

2. Real objects (such as real trees) exist in uneasy alliance with their qualities

3. Real objects are deeper than the phenomenal qualities that emanate from them in relations

4. Intentional objects are unreal but are made up of real moments

This fourfold of accidents, relations, qualities, and moments can be restated in cosmologically more interesting fashion:

1. The tension between an intentional object and its accidents is precisely what we mean by TIME

2. The withdrawal of a real object from any relation is what we call SPACE

3. The duality between a real thing and its own real qualities can be called ESSENCE

4. A merely intentional thing’s possession of genuine qualities can be called, in a Husserlian sense, EIDOS

I feel that we need to ask how much of this falls back upon the essentialized notion of central clarity, the idea that our minds should be directed (philosophically) towards the focus upon “intentional objects” or “real objects” (or the interplay between them); how much does this direction rely upon a mistaken over-simplified “picture” of consciousness, and the historical inheritance of conceptions derived from Descartes fascination with refraction and the correction/enhancement of vision? It seems that when we realize that it is rather the “accidents” of an object that actually compose our intentionality, the eruptive semiotics of a dissonance that flows out from a ground of sense-making, the game of recapturing the buried “essence” of an object, the “real” object, apart from its intentionality loses its footing. It is the accidents themselves that connect us to the object, the flash of light across a surface that redirects our orientation to the object and causes us to care about it in a new way, to encamp it with a cathexis of our informing affects, and understand the world differently through these connective effects. When the intentionality of consciousness is understood not directed towards a clarity, an object (however present or hidden), but rather towards the breakdown of that object, not through an attention to the regain of an eidos behind it, but through a bodily reconfiguration of ourselves in orientation to the world itself wherein there is no accident for each accident signifies, then we understand the mind much more as an activity rather than a representation device (an important step I feel). It is in this constant re-vectorialization of the self through reporting others and a world that gives knowledge its uumph, its power and freedom. I am unsure how far Graham Harman’s Object-Oriented Philosophy deviates from my thoughts on this, for we share a distinct interest in the post-human, a sense that flat ontologies should be in some ways deepened, and would work toward a cybernetic understanding. I look forward to a continual and edifying communication with Graham Harman’s writings, in particular the coming book on Latour, Prince of Neworks. These thoughts come out of what for me was a strong sense that he yearns for a solidity behind (or in front of) the orientation of philosophy, a solidity which he reads as “depth”, yet an anchor point which by my brief reading takes its cue from a tradition that pursues a central clarity in what for me are misleading metaphors of vision, a tradition which works to stablize and centralize the human self (soul) which he looks to de-centralize.

In addition to this, as a last remark, there is in modern philosophy a tendency to think in irreducible dyads, that is: How do we get from here (let us say, that intentional object) to there (the real object); or how do we get from here (a true proposition) to there (a state of the world); or how do we get from here (thoughts in my mind) to there (thoughts in your mind); or most generally, how do we get from here (the self) to there (the world). This binary thinking which haunts much of representational analysis is a continuation of the primary problem of much of theology, how to get the soul back to God. All kinds of mediating paths are offered to what is imagined to be a fundamentally binary relationship (we expect the mediations to vanish). Many of these philosophical conundrums disappear when the dyad turns into a triad (and not a Hegelian triangle), that is, when the A/B line becomes a triangle of orientations. This is part of Latour’s philosophy of the “same”, but also central to Donald Davidson’s triangulation. It is not self/world, but self/self/world. I think part of the problem of thinking in terms of mind/object-essence dyads is that the triangle does not become properly emphasized. What happens when we find a fissure at the center of consciousness is that the third term (be it another informing person/object, or a causal state of the world) comes into view to help consolidate the fissure, bringing it into a clarity which then erupts. The fullness of a philosophy should be directed towards the necessity of the third term in any binary preoccupation, the way in which the third completes the sense. Not Object-Oriented Philosophy, but Oriented Object Philosophy, perhaps.

As Plotinus tells us:

If they are two, the knower will be one thing, and the known the other, and contemplation (theõria) has not yet made this pair akin to each other (õieiõsen) (Enn. 3.8.8). 

For thoughts related to these:

1. A Diversity of Sight: Descartes vs. Spinoza

2. The Hole at the “Center of Vision”

3. Deciphering Spinoza’s Optical Letters

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Some Observations on Spinoza’s Sight

How The Two Philosophers “See”

I feel that there are some important things to say about my recent post, A Diversity of Sight: Descartes vs. Spinoza , but I am still undecided just how deep the influence of these thoughts run. So pervasive is the metaphor of vision and light within Western metaphysics, any identification of an ocular appropriation into the field of metaphysics, and the questioning of its radical truth or application, may have far reaching interpretive effects.

What may prove the advantage of this analysis is that it promotes a simplification. Like all simplifications it is misleading to take this as the whole story, but it does help us identify a core element of disagreement between the two Natural Philosophers. The difference between Descartes and Spinoza cannot be reduced to these two diagrams, of course. But there is an essential divergence in the thinking about vision as a metaphor for thought that is expressed in them. 

Descartes' Ur Image: The Hyperbola

Spinoza's Ideal Optical Eye

The first of these, for those uninterested in the optics under question in Spinoza’s letters 39 and 40, shows the capacity of a hyperbolic lens to focus any rays that are parallel to its central axis to a point along that axis. What the hyperbola provides is a schema for thinking about vision and clarity, the analogy of imagining that a focused image of the world that is “clear and distinct” is one where all the rays of a kind are brought to a mathematical ideal, poured into a point. We are not dealing here with all the details of lenses, and how they interact with the human eye and light in the fullness of their variety, but rather with a guiding diagram of what a lens should do – focus rays of light to a center point – and what that means for the experience of vision. For this reason, it is best to understand that this image for Descartes is likely intuitive of directions for investigation, steering both his theories and empirical observations.

The second of these is from Spinoza’s Letter 39, and works as a vivid contrast to Descartes’ Hyperbola. Instead of imagined parallel rays focusing down into an ideal point in the very center of the eye (which in some ways Descartes will conflate with the free Will), for Spinoza the Ideal Eye is one that in using the properties of a circle is able to focus rays parallel to a variety of axes (in fact, an infinity of axes). Rays coming from all directions are hoped to be focused across the back of the eye. And Spinoza sees the human eye (insofar as it does not have a spherical lens), as failing to achieve this kind of vision. Ideal mental vision, instead of being modeled upon a central point of focus, Spinoza conceives of as panoptical; that is, one “sees” as best as a human mind can the cross-section of rays as they converge from every direction upon the human being.

As admitted, this is truly a vast over-simplification, for much unites these two philosophers, and the kinds of radical divergences that Spinoza makes are must more diverse than this simple diagram comparison. But really there is something suggestively profound in this contrast. For one, in that Descartes’ hyperbola inheritance may be traced to Kepler’s Paralipomena its conceptual framework should be viewed as grafted from that Neo-Platonic Ideal, opening up the question of what aporias arise under such a graft (for instance, a point of focus in a Neo-Platonic realm, does not operate with the same powers or meanings as a point of focus does within a Will-driven conception of the soul). Additionally, Spinoza’s rejection of the naturalization of the hyperbola, and the analogy of center-focused human vision, has far-reaching consequences for the reading of the place of the Self in his philosophy of power and affect. If Ideal vision occurs across a field of foci, the periphery has no less a “truth” than any center. The margin does not merely, as Kepler says, “serve” the axis – so goes the critique in so many postmodern attacks on a philosophy of Presence – hence the margin is the very place where a search for truth is made, whether it be the margin of society or a comprehensive Totality of Being.

It is my hope that these two sketches of focus, one by Descartes and one by Spinoza, can help draw out the more refined differences of both philosophers, along an analogy of sight.

A Diversity of Sight: Descartes vs. Spinoza

Different Foci of “Clear and Distinct”

This may be premature in my process, but I would like to set down some simple correspondences that have arisen in my reading of Kepler’s Paralipomena to Witelo (1604), correspondences that elicit strong tidal differences between Descartes’ approach to vision – with its attendant metaphysical counterpart, the clear and distinct Idea – and Spinoza’s. That this is found in some of the historically least interesting of Spinoza texts, what has been taken by many to be Spinoza’s blundering into optical theory [ letters 39 and 40 to Jelles, full text ], is suggestive of Spinoza’s critical brilliance. For within Spinoza’s conception of optics and his close-cut rejection of Descartes reasoning seem to be important radical divergences, insofar as vision and light are understood to be more than analogous of metaphysical truths. In these letters Spinoza questions the very vision-philosophy that privileges a central-line of axis, one that fundamentally connects a viewer within to an external and opposing point: a hidden, underpinning assumption of Descartes’ mathematization of the experiential self, Will and the world. Though there is much in Descartes’ philosophy that substantially departs from the Perspectiva epistemology tradition, his enthused embrace of the powers of the hyperbola embody a grounding of the eye, (and therefore the mind), in a centralized perception and knowledge upon which Spinoza places his criticism.  

I have not encountered any analysis which shows that Descartes’ enthusiasm for the hyperbola derives directly from Kepler’s Paralipomena, yet as I am not fully familiar with the literature perhaps this is a commonplace understanding. Gaukroger, for instance, gives evidence that Descartes read this text around 1620, and allows three possible points of influence, but does not speak to the potential influence of Kepler’s offer of the hyperbola as a natural normative of vision. Yet in the process of reconstructing Spinoza’s conceptions in these two letters of objection to Cartesian optics this connection with Kepler owes be fleshed out. One will see that in the Paralipomena Kepler not only sets out the virtues of the hyperbola’s anaclastic line in terms of its resolution of spherical aberration from focus – the primary and crowning demostration of Descartes’s 8th discourse of La Dioptrique – but he also naturalizes the hyperbola, claiming that the hyperbolic shape of the posterior of the crystalline humor is the very thing that helps establish the soul’s satisfaction with centered-object viewing. In fact, the wide sweep of Descartes’ metaphysics and optics in brief seems signaled by Kepler in his treatment of the hyperbola. And, because I suspect that Spinoza has Kepler’s descriptions in mind when responding to Jelles, making an argument for the importance of a radii of axes of perception, and emphasizing the importance of the angle of incidence in the measure of magnification (see letters linked above), his alternate response to Kepler provides a valuable clue to the stake Spinoza is making against Descartes, both in philosophy and science. In short, Descartes makes a virtue out of the Kepler’s description of the hyperbola and the eye, and Spinoza makes it something of a flaw or limitation. 

Setting Forth Kepler’s Hyperbola

Kepler's illustration exploring the properties of refraction, page 106

First, perhaps it is best to set out what Kepler has to say about the hyperbola so that a comparison can be made. Initially, he embraces the figure in an attempt to assess a law of refraction, which he hopes to find through the virtue of its special properties. He will not attain the law of refraction, but what he does make clear is that the hyperbola alone possesses the capacity to focus parallel rays to a single mathematical point, or vice versa. Thus, he writes of the figure above:

What is required is to say what sort of surface it is upon which these radiations in this position coming forth from α, so that they strike just as do here the lines βλ, μγ, and so on, so that these lines are either tangents to that surface, or lines equidistant to the tangents…These, moreover, are found only in the hyperbola, not in the parabola, which tends toward a straight line parallel to the axis, not one meeting the axis, as X A here. (107-108).

Not to get lost, were are simply establishing that Kepler points out the solitary characteristic of the hyperbola which will make a lens of this shape central to Descartes’ ambitions for providing aberration-free vision through hyperbolic lenses.

The next apparence of the hyperbola in Kepler’s text occurs in chapter 5, where the geometry and anatomy of the human eye is discussed. Here Kepler presents a small, simple drawing of the “crystalline humor” which behind the cornea in the eye is the primary means of focusing light. I enlarge it here for clarity:

Keplers drawing of the crystalline humor

Kepler's drawing of the crystalline humor, page 167

Kepler writes of the shape of the humor:

 On the posterior side…[the] figure is a hyperbolic cononoid, a hyperbola rotated on its axis. For [Johannes] Jessenius thus relates, that it is not spherical as [Felix] Platter said but that it protrudes markedly, and is made oblong stretching up almost into a cone; and that on its anterior face it is of a flattened roundness…(167).

Kepler has emphasized a correction. The humor is not spherical as Platter claimed, but hyperbolic, and made nearly like a cone. It is this particularity of the eye, coupled with his earlier hyperbolic observations that will create a certain naturalization of hyperbolic vision, something that speaks to the very nature of the human soul. The aspherical effect of the crystalline humor on vision is made clear a few pages later where Kepler discusses how the various cones of light coming from each of the points of an object to be seen, interact with and refract upon the cornea and the crystalline humor. What will be shown is that the humor is biased towards the production of clarity oriented towards its central axis, and that light cones that come obliquely to this angle, will appear less clear to the human eye, as they are focused to the borders of the image:

All the lines of the direct cone [whose axis is the same as the axis of the cornea and crystalline] are approximately perpendicular to the crystalline, none of those of the oblique cones are. The direct cone is cut equally by the anterior surface of the crystalline; the oblique cones are cut very unequally, because where the anterior surface of the crystalline is more inclined, it cuts the oblique cone more deeply. The direct cone cuts the hyberbolic surface of the crystalline, or the boss, circularly and equally; the oblique cone cuts its unequally. All the rays of the direct cone are gathered together at one point in the retina, which is the chief thing in the process; the lines of the oblique cones cannot quite be gathered together, because of the causes previously mentioned here, as a result, the picture is more confused.The direct cone aims the middle ray at center of the retina; the oblique cones aim the rays to the side…(174)

Kepler then takes these facts of refraction and uses them to explain the experience we have of satisfactory vision. What is most notable is that Kepler wants us to understand how the oblique “more confused” images at the borders of an image actually complete and serve the focus of vision around the central axis:

…so the sides of the retina use their measure of sense not for its own sake, but whatever they can do they carry over to the perfection of the direct vision. That is we see an object perfectly when at last we perceive it with all the surroundings of the hemisphere. On this account, oblique vision is least satisfying to the soul, but only invites one to turn the eyes thither so that they may be seen directly (174). 

The “surroundings of the hemisphere” invite our eye from to this or that. Oblique vision proves satisfying to the soul only to the degree that it inspires the eye to turn its hyperbolically-aided central axis across its field. The concept is that the deprivation of clarity somehow drives the soul to complete its picture. This is an important point when considering the influence of vision as a primary analogy for Cartesian metaphysics.

Kepler Completes the Synthesis of Eye and Lens

Lastly, Kepler will place the facts and inclinations of vision within the context of the powers of hyperbolic focus, and he does this in such a way that it would seem sure that when Descartes looks to solve the problem of spherical aberration he would see in the hyperbola a natural bias towards centralized focus.

Keplers illustration of the spherical aberration of rays

Kepler's illustration of the spherical aberration of rays, page 194

After a protracted investigation of the behavior of light rays in refraction through a crystal globe filled with water, and an explanation of our visual experiences of the images and confusions that result, Kepler will conclude that the hyperbola alone resolves the need for gathering a cone of rays into a single point:

Proposition 24 – Rays converging towards some single point within a denser medium are gathered by the hyperbolic conoidalsurfacebounding the medium to one single point, closer than the former point…These two things [two requirements], however, are accomplished, not by one or another circle but by conic sections…Further, of the conic sections, only the hyperbola or some line very close to it, is the measure of refractions, as was shown in Sect. 5 of chapter 4. Indeed, this very thing was demonstrated there: that the surface making all the rays outside the denser medium parallel is a conoid that does not differ from hyperbolic (198).

Given this remarkable property, Kepler then concludes that “nature’s plan” has endorsed the priorty of the hyperbola. And it seems that there can be little doubt that Descartes worked to synthesize this priorty which his own metaphysical priorty for “clear and distinct” ideas:

Hence it is evident nature’s plan concerning the posterior surface of the crystalline humor in the eye. That is, she wished to gather all the radiation of any visible object entering the opening of the uvea [pupil] into a single point of the retina in order both that the point of the picture might be all the more evident, and that the rest of of the points of the picture might not be confused by extraneous rays whether stray or gathered together. – Chapter 5, proposition 24, corollary (199).

Spinoza: “the eye is not so exactly constructed..” (letter 40)

To pull back for a moment. If this analysis is correct, that a decisive rift in Cartesian philosophy could be seen in Spinoza’s letter to a friend discussing what at most appears to be a trivial oversight on Descartes’ part is striking. Many scholars seem to have struggled over the meaning of Spinoza’s words in these letters (39 and 40) sensing that there is an elementary blunder in Spinoza’s thinking, but, as seen in their lack of a careful examination of it, there is an inability to locate just what this blunder would be. Instead, because Spinoza has been read as solely a metaphysician, his foray into optical matters in these two letters was largely dismissed as Spinoza simply wading in too deep a water. With very few exceptions, most only assumed that Spinoza was unfamiliar with the issues at stake, and his in-concordant use of terms appeared to prove this; yet a change in scholarship is occurring. Perhaps our examination of these two letters can add to this shift of perspective.

What does Spinoza mean in his letter 40 talk about the inexactness of the human eye?:

Moreover, it is certain that, in order to see an entire object, we need not only rays coming from a single point but also all the other rays that come from all the other points. And therefore it is also necessary that, on passing through the glass, they should come together in as many other foci. And although the eye is not so exactly constructed that all the rays coming from different points of an object come together in just so many foci at the back of the eye, yet it is certain that the figures that can bring this about are to be preferred above all others (letter 40, full text)

We have seen from Kepler that the likely reference is to the distortions of “more confused images” at the borders of vision, in part due to the aspherical, single axis nature of the eye’s lenses. This stands in contrast to Spinoza’s diagram, which he takes to be an ideal spherical refraction: 

Spinozas diagram of the virtue of spherical refraction, Letter 39

Spinoza's diagram of the virtue of spherical refraction, Letter 39

Spinoza is extolling the comprehensive capacities of spherical refraction, and his embrace of this concept marks out a distinct divergence from Descartes’ naturalized emdorsement of a center-focused vision.  Descartes will develop a theory of clear and distinct thinking which narrows the field of mental vision. This vision is imagined to be in concert with what Nature had planned in having given the eye its own hyperobolic lens; conversely, Spinoza will take from Descartes the notion of “clear and distinct”, but the concept of vision in which it is to be deployed is dramatically different. Spinoza emphasises the clarity of a connective, hemispherical scope; Descartes is aimed at the close focus on the surest of things.

Looking With the “Mind’s Eye”

This difference perhaps can be made more distinct by considering the use of the phrase “the Mind’s eye” by both thinkers. For instance, in his Regulae, after his very influential Rule 8 [the full text of which I post and briefly engage here ], Descartes tells us in Rule 9 how we must compare improvements in thinking by attending to how we naturally see things. Human vision provides the exemplar of how of mental vision is, and the issue is one of central focus:

Rule 9: We must concentrate our mind’s eye totally upon the most insignificant and easiest matters, and dwell upon them for long enough to acquire the habit of intuiting the truth distinctly and clearly.

…We can best learn how mental intuition is to be employed by comparing it with ordinary vision. If one tries to look at many objects at one glance, one sees none of them distinctly. Likewise, if one is inclined to attend to many things at the same time in a single act of thought, one does so with a confused mind. Yet craftsmen who engage in delicate operations, and are used to fixing their eyes on a single point, acquire through practice the ability to make perfect distinctions between things, however minute and delicate. The same is true of those who never let their thinking be distracted by many different objects at the same time, but always devote their whole attention to the simplest and easiest of matters: they become perspicacious.

– Descartes, The Regulae, Rule 9

It is not without significance that Descartes in his metaphor of close focus appeals to artisans and craftsmen to praise the powers of concentrated vision. These are not a class of persons that he would embrace in society- his attitude toward de Beaune and Ferrier is well known – but their analogous use in a hierarchy of powers is in keeping with his concept of knowledge being like an ascent of mechanized complexity, from primitive mental tools to those most intricate (Rule 8, Regulae). The same artisan trope is found again in his La Dioptrique, where the limits of the eye are by craftsmen strained and improved by the exercise of ocular muscles. I quote at length below because it is an important passage. For one, it is found at the end of the 7th Discourse which is the text that Spinoza and Jelles are commenting on in their letters, and is at the cusp of his presentation of the 8th Discourse praise of the hyperbola. Secondly, here the virtue of a dispersive vision (which Kepler describes as limited by the hyperbolic shape of the lens) is denied: seeing more is not seeing better, as is testified by experience; and thirdly, Descartes treats the possible alteration of the limits of crystalline humor and pupil’s capacities as being achievable, not in the direction that Spinoza would like (tpward a more-than-human breadth of clear vision), but in terms of an exceedingly close narrowing, achieved by trained specialists:

There is only one other condition which is desirable on the part of the exterior organs, which is that they cause us to perceive as many objects as possible at the same time. And it is to be noted that this condition is not in any way requisite for the improvement for seeing better, but only for the convenience of seeing more; and it should be noted that it is impossible to see more than one object distinctly at the same time, so that this convenience, of seeing many others confusedly, at the same time, is principally useful only in order to ascertain toward what direction we must subsequently turn our eyes in order to look at the one among them which we will wish to consider better. And for this, Nature has so provided that it is impossible for art to add anything to it.

I have still to warn you that the faults of the eye, which consist in our inability to change sufficiently the shape of the crystalline humor or size of the pupil, can bit by bit diminish or be corrected through practice: for since this crystalline humor and the membrane which contains this pupil are true muscles, their functions become easier and greater as we exercise them, just like those of other muscles of our body. And it is in this way that hunters and sailors train themselves to look at very distant objects, and engravers or other artisans who do very subtle work to look at very close ones. 

– Descartes, Seventh Discourse

In the highlighted passage Descartes repeats Kepler’s summation of the benefits of a hemisphere of vision, that it simply leads to a field of vision which helps serve our central axis: Kepler: “On this account, oblique vision is least satisfying to the soul, but only invites one to turn the eyes thither so that they may be seen directly “. Yet Descartes has changed the emphasis some and placed the notion of “willing” at this central axis (a literal conflation). The widening of a view only provides the occasion for free choice, which will express itself in the turning of the single axis of the eye. (It is thus clear that Descartes and Spinoza mean different things by “the faults of the eye” and “the eye is not so exactly constructed”.)

Spinoza: “so that we must not fall into pictures”

What is compellingly consistent is that Spinoza’s own use of Descartes’ “Mind’s eye” phrasing will directly address the Cartesian issue of the freedom of the will, not to mention the pictorial conception of clarity and distinctness. The phrase is most pointedly found in his Ethics, just where the distinction between willing and understanding is by Spinoza denied (E2p48 and 49):

E2p48 – In the mind there is no absolute, or free, will, but the Mind is determined to will this or that by a cause which is also determined by another, and this again by another, as so to infinity.

Scholium – We must investigate, I say, whether there is any other affirmation or negation in the Mind except that which the idea involves, insofar as it is an idea – on this see the following Proposition [49] and also D3 – so that our thought does not fall into pictures. For by ideas I understand, not the images that are formed at the back of the eye (and, if you like, in the middle of the brain), but concepts of Thought [NS: or the objective Being of a thing insofar as it consists only in Thought]; – trans. Curley

Descartes’ notion of looking with the “Mind’s Eye” requires learning what distinctness is in terms of our experience of human vision, a lesson that requires that we focus closer and closer upon obvious things, training our eye to become more and more exact, a lesson which in turn gives us to understand the centrality of the focus of a single axis, and the use of a breadthof vision as merely the field for a freedom of choices; yet in Spinoza the human eye itself is seen as “inexact” in its singular axis of focus. And looking with the Mind’s eye is for Spinoza not so much a process of learning to see clearer and clearer pictures, (or even holding one clear idea or another in mental vision), but rather learning to look in a way quite unlike the way of the human eye, within a matrix of conceptual understandings; and this matrix is one which decenters the central axis of vision (and one could say the “self”), strives to achieve something akin to an infinity of axes of vision, (nothing more than a breadth understanding of the order of Adequate Ideas and thus the causes of the phenomena we witness, and that we affectively experience). While Descartes would say, following closely our analogous experiences of human vision, that seeing more is not seeing better, Spinoza would say that one is only seeing better if one is seeing more: hence his thought moves very, very quickly to the intuition of the Adequate Idea of God.

A Difference in Method

One grasps this if one compares Descartes’ notion of method with Spinoza’s own early Emendation notion of method, which is in response to it. The below passage is important because it follows several points which bear 8th Rule influence (a focus upon human powers, viewing knowledge building like blacksmithing, for instance). While Descartes is interested in focusing the mind on simple truths which may serve ultimately to connect one to a transcendent God, Spinoza’s method is not one of focus upon this or that truth, but upon the standard of truth itself as it immediately directs one’s attention to a maximalizationof thought: a most perfect Being. It is the distinction between one kind of perception and all others, which throws the vision wide:

That is, the most perfect method will be one which shows how the mind should be directed according to the standard of a given idea of the most perfect Being…From this one can readily understand how the mind, as it understands more things, at the same time acquires other tools which facilitate its further understanding. For, as my gathered from what has been said, there must first of all exist in us a true idea as an innate tool, and together with the understanding of this idea there would likewise be an understanding of the difference between this perception and all other perceptions. Herein consists on part of our method. And since it is self-evident that the more the mind understands Nature, the better it understands itself, it clearly follows that this part of our method will become that much more perfect as the mind understands more things, and will become then most perfect when the mind attends to, or reflects upon, the knowledge of the most perfect Being. (trans. Shirley 39)

The web of truths that “Mind’s eye” vision focuses on is a breadth of vision, governed by a comprehension of determined causes. And in a sense, this begins with God, God as a totalizing reality of Being from which we are not separate. A field of vision, which for Descartes provides an array of choices which an axis-eye then willfully judges and picks its way through, for Spinoza is an incandescent weave of causes and effects, any adequate understanding of which leads to all others. It is a spherical conception of a refraction along an infinity of axes, in which the Will plays no part.

Descartes’s Hyperbolic Doubt and Hyperbolic Lens

In considering Kepler’s introduction of hyperbolic lenses and his Nature’s single-axis plan for the eye, and then Descartes synthesis of the two, there is the happy result of support found for a contested interpretation of Descartes offered by Graham Burnett, in his book Descartes and the Hyperbolic Quest . Professor Burnett offers that Descartes’ obsessive, mechanized pursuit of the grinding of a hyperbolic lens, and his project of legitimatizing his Natural Philosophy through “hyperbolic doubt” are something more than a mere conflation of uses of the word “hyperbolic”. Burnett tells us, citing Gaukroger’sbiography, that the two may correspond to a single conception of mind, (quoting at length):

What configuration of mind of mind allows natural light to coalesce into a clear and distinct idea? The answer…is hyperbolic doubt. If once we saw, as in a glass darkly, and if at some (beatific) point we will see face to face, for the time being the best we can seem to do is to see through the right kind of glass that one that does not distort or obscure: and this just might be, at least least initially, the focusing glass of hyperbolic doubt. To play out the suggestion then: Descartes greatest scientific success lay from his perspective, in his systematic investigation of optics and the perfection of human vision those investigations promised; his optics presented an instanteous light that could be focused into clear and distinct images by means of the imposition of ahyperbolic form. Descartes’ greatest philosophical success lay, from his perspective, in a systematic investigation of the human mind and the perfection of cognitive operations those investigations promised; that the human mind received, via natural light of reason, an instanteous, clear and distinct illumination, but only by means of the interposition of another hyperbolic focusing device – the hyperbolic doubt.

I do not wish to overemphasize the signification of the parallelism, tantalizing as it is. Following Gaukroger’s reconstruction of Descartes’ psychology [Descartes, an intellectual biography ], a quite elaborate extension of the hyperbolic (lens)/hyperbolic (doubt) analogy would be possible. In Gaukroger’s reading, the imagination mediates between the pure intellect and the realm of the senses, and the experience of cognition inheres in this intermediate faculty, which represents the content of the intellect and the content of the senses both as “imagination.” Where these two map onto each other the experience is that of “perceptual cognition.” As the project of hyperbolic doubt is abundantly imaginative, and as Descartes has insisted that the natural light of reason does not stream down from God but is within our intellects, it would be possible to argue that the imagination plays the role of the focusing of the hyperbolic lens, and receives the light emanating from the intellect, which normally enters the imagination confusedly, quickly distorted by the “blinding” profusion of imagery from the senses (126-127).

Indeed, if we follow professor Burnett’s conclusion, and allow it to have a substance greater than mere lexical coincidence, we find that when armed witha knowledge of Kepler’s antecedent approach to the hyperbola such a reading begins to cohere. Descartes’ embrace of Kepler’s hyperbola of the human eye shows that “extreme doubt” and the focus of the Will that it accomplishes is for Descartes truly both a mechanism for focusing the mind upon simple truths and a naturalized legitimization of a will-centered, single axis organized perception. What professor Burnett intuited through his study of Descartes’ life-long pursuit of an automated, hyperbolic lens-grinding machine, is given traction when the genealogy of Descartes’ conception of the importance of the hyperbola is traced back to Kepler, its orgin. And this is exposed in two almost-ignored letters written by Spinoza on a subject he long had been considered deficient in, as the force of Spinoza’s attack upon both Descartes’ metaphysics andhis optics is to be considered as being of one cloth. Spinoza has Kepler in mind because Descartes had Kepler in mind. This is suggestive of the power of Spinoza’s critique, and the level at which he carried it forth. It touched not only the abstraction of Descartes’ metaphysics, but also the optical-theory origins of Descartes preoccupation, that human vision was somehow naturally hyperbolic and therefore offering a guide toward the perfection of the mind. Because our inheritance of the optical trope of human vision is so rooted in our conceptions of the world, and our acceptance of Descartes’ approach to thought and mechanism is so pervasive, Spinoza’s optical critque proves promising of a radical importance at the very least.

Lasting Questions

None of this goes any distance toward proving whether Spinoza’s critique of Descartes in letters 39 and 40 was correct in the terms he meant it by, speaking of how light and lenses behave. Clearly Spinoza was well informed about the nature of Descartes’ claim as to the importance of the hyperbola. He had read and followed Johannes Hudde’s Specilla circularia, which dismissed the importance of spherical aberration in a mathematically exact way, minimizing Descartes’ impractical solution; and he was likely familiar with ChristiaanHuygens’ own complaints about Descartes’ failures in treating telescope magnification accurately. Additionally, it seems quite likely that Spinoza was familiar with the Ur-source of Descartes’ own embrace of the hyperbola, Kepler’s Paralipomena to Witelo, since he addresses specific terms of its explanation, and the argument he presents in brief cuts to the quick of the virtues of the hyperbola presented there: the idea that the human eye’s hyperbola somehow expresses Nature’s plan which in Cartesian hands would naturalize a priorty of a single-axis, will-driven priority of focus and choice. By arguing for the “inexactness” of the eye, Spinoza is undermining a primary vision/knowledge metaphor which helps form part (but most certainly not all !) of Descartes’ metaphysics of clarity.

There are therefore a few questions that remain. For one, Kepler does not merely serve as a source for a negative critique of Descartes, insofar as he has followed Kepler. For instance Kepler’s conception of light in many ways diverges from Descartes’, and could be said to have concepts which presage Christiaan Huygens’ own wave theory, which would eclipse Descartes’ optics. It remains to be seen if Spinoza’s optical understanding stems directly from Kepler in a positive sense, that is, if Spinoza’s holds optical concepts which were superior to Descartes’ theories due to Kepler’s influence. Spinoza has used Kepler to undercut Descartes’ metaphysics, but where does Spinoza stand in terms of contemporary optics? For this to be answered, Spinoza’s praise of the versatility of an infinity of axes has to be set up against the contemporary science of telescope construction. For though Descartes’ hyperbolic lenses were nearly impossible to make at that time, in theory at least they would have offered an advantage. Spinoza’s objection is that Descartes is incomplete in his analysis of magnification, and that the capacity of a lens to handle a variety of axes is important in compound telescope magnification. Such a possible importance remains unaddressed, though all existing telescopes obviously achieved their magnification without hyperbolic lenses (and notably, Christiaan Huygens had privately solved the issue of spherical aberration using only spherical lenses in the summer of 1665, when Spinoza and he were closest).

The other question that remains is to determine the large scale consequences of Spinoza’s rejection of a naturalized, single-axis concept of hyperbolic vision, upon his own preoccupation with lens-grinding and instrument making. The grinding of a lens, after all, is exactly the kind of “craftsman” or “artisan” practice that Descartes lauded in his 9th Rule, one that lead to an acuity of vision. The purpose of a lens is most often to achieve a magnification which concentrates the vision at a local point. And this is the mode of narrow focus to which Spinoza seems to making his objection. But if we allow the analogy between craftwork and mental tools found in the works of both Descartes and Spinoza, the careful refinement of a proposition, such as those found in Spinoza’s Ethics, would be read as a kind of development of perspicuity. Permitting the Ethics to stand as our model for complex, intricate knowledge, by analogy any grinding of glass into a polished shape must be seen as part of an interlocking of all other actions, ideas and material states; for just as there is extensive cross-reference in Spinoza’s Ethics, Spinoza’s own daily preoccupation with lens-grinding and instrument building must be seen as cross-referenced to an infinity of other causes and actions, all leading to an theorized increase in freedom. As Spinoza clarified a piece of glass and made it capable of magnfication, was it that he was concerned not just withthe the lens, but how this magnification fit with other lenses, in devices, with phenomena to be discerned, and the Ideas we hold as we use them? It would seem at that this is so, but this question has to be answered more fully.

 

 

Descartes and Spinoza: Craft and Reason and The Hand of De Beaune

Some Reflections on Letter 32

Descartes in 1640 reports to Constantijn Huygens, “You might think that I am saddened by this, but in fact I am proud that the hands of the best craftsman do not extend as far as my reasoning” (trans. Gaukroger). And as Graham Burnett translates, “Do you think I am sad? I swear to you that on the contrary, I discern, in the very failure of the hands of the best workers, just how far my reasoning has reached” (Descartes and the Hyperbolic Quest, 70).

The occasion is the wounding of the young, brilliant craftsman Florimond De Beaune on a sharp piece of glass, as he was working to accomplish the automated grinding of a lens in a hyperbolic shape on a machine approximating Descartes’ design from La Dioptrique. This at the behest of Descartes himself:

His wound to the hand was so severe that nearly a year later De Beaune could not continue with the project, a project he would not take up again. Descartes’ craftsmanless, all-turning machine could not be achieved. It is as if its “reason” had chewed up even the best of earth’s craftsman.

Compare this to Spinoza’s comment on Christiaan Huygen’s own semi-automated machine, in letter 32 to Oldenburg. (One wonders if he may even had had a now infamous injury to De Beaune in mind.) Descartes seems to write callously to Christiaan’s father in 1640 [following Gaukroger’s citation], 25 years later Spinoza writes soberly about the machine of the son:

…what tho’ thusly he will have accomplished I don’t know, nor, to admit a truth, strongly do I desire to know. For me, as is said, experience has taught that with spherical pans, being polished by a free hand is more sure [tutius] and better than any machine.

Issues of class play heavily into any attempt to synthesize the rationality of a mechanism with the physical hands [and technical expertise] of the required craftsman to build it. What comes to mind for me is the same Constantijn’s Huygens enthused reaction to the baseness of the youths Rembrandt and Lievens in 1629, when he discovered their genius. As Charles Mee relates and quotes:

Unable to have Rubens, Huygens evidently decided to make his own Rubens, and he saw the raw material in Leivens and Rembrandt. He loved the fact that this “noble pair of Leiden youths” came from such lowly parentage (a rich miller was still a miller after all): “no stronger argument can be given against nobility being a matter of blood” (Huygens himself had no noble blood). And the fact of their birth made the two young men all the more claylike, so much more likely to be shaped by a skilled hand. “When I look at the teachers these boys had, I discover that these men are barely above the good repute of common people. They were the sort that were available for a low fee; namely with the slender means of their parents” (Rembrandt’s Portrait ). 

The standing of the rising Regent riche had to position itself between any essentialist noble quality of blood, and the now stirring lower merchant and artisan classes, whose currencied freedoms in trade and mobility were testing ideological Calvinist limits. Leveraging itself as best it could on rational and natural philosophy, a philosopher-scientist-statesman was pursuing a stake in freedom and power, one that rested on the accuracy of his products. In this way it seems that Descartes’ – feigned? – glee over De Beaune’s injury, insofar as it embodied a superhuman outstripping of remedial others, manifests this political distancing to a sure degree. De Beaune was no ignorant worker, for his high knowledge of mathematics made him much more “technician” than craftsman, (in fact de Beaune had proposed the mathematical problem of inverse tangents which Descartes would not be clear on how to solve (letter, Feb 20 1639), and it was his Notes brièves and algebraic essays which would make Latin editions of Descartes Géométrie much more understandable to readers). Reason and rationality could in the abstract certainly in some sense free even the most economically and culturally base kinds (at least those with a disposition to genius), but in fact savants likely imagined that their lone feats of Reason actually distanced themselves from the “hands and limbs” on which they often relied.

Seen in this way, Spinoza’s sober view of Christiaan Huygens machine perhaps embodies something more than a pessimism of design, but rather more is a reading of the very process of liberation which technological development represented for a class of thinkers such as Leibniz or the Huygenses. The liberation of accuracy and clarity was indeed a cherished path, but perhaps because Spinoza was a Jewish merchant’s son, excommunicated, because Spinoza understood personally the position of an elite [his father had standing], within a community itself ostracized though growing with wealth, a double bind which he relinquished purposively, any clarity was necessarily a clarity which connected and liberated all that it touched. It was inconceivable to have dreamed a rationality so clear that it would distance itself from the the hands that were to manifest it. Perhaps Spinoza keeps in his mind the hand of De Beaune.

To Understand Spinoza’s Letter 32 to Oldenburg

It is November of 1665, and Spinoza has just that summer likely spent much time in communication and possible visitation with the esteemed Christiaan Huygens, whose estate is a mere 5 minutes walk from where he lives. The two of them are ensconced in the quiet village of Voorburg, but it was a summer in which plague was ravaging London at a rate of nearly 6000 a week, and the secretary of the Royal Society of England, Oldenburg, has begged Spinoza for an update on the discoveries and devices of Huygens, as if upon such innovations the figurative health of society depends.

Spinoza responds with some telling remarks, upon which I have already registered some thoughts: Spinoza’s Comments on Huygens’s Progress. Here though, I want to post some relevant illustrations from Huygens’s notebooks, which make much more clear just what Spinoza may find objection to in Huygens’s fabrica. What Spinoza writes is this:

The said Huygens has been a totally occupied man, and so he is, with polishing glass dioptrics; to that end a workshop he has outfitted, and in it he is able to “turn” pans – as is said, it’s certainly polished – what tho’ thusly he will have accomplished I don’t know, nor, to admit a truth, strongly do I desire to know. For me, as is said, experience has taught that with spherical pans, being polished by a free hand is safer and better than any machine.

(This was the summer that Huygens will have solved the issue of spherical aberration using a solely combination of spherical lenses. But Spinoza does not know this.) We can assume that Spinoza has seen the machine that Huygens is fast at using. In order to see with Spinoza what this machine likely entailed, one must turn to several illustrations. Since the 1650s Huygens had experimented with (and likely used) an assisted means of steadying the glass blank against the spinning metal grinding form. The nature of this technical strategy was a long “bâton” which would restrict the kinds of movements the blank was capable of:

This is a detail of the device, followed by the wide view:

Oeuvres Complètes, XVII (p.300)

Oeuvres Complètes, XVII (p.299)

As one might see, the glass blank can toggle to a degree. This is what professor Graham Burnett writes of it in his Descartes and the Hyperbolic Quest: Lens Making Machines and Their Significance in the Seventeenth Century:

In the late 1650s, [Huygens] outlined the improved “bâton” technique for handling the lens in the forming pan [above illustrations cited]. Previously, the lens blank had been afixed by means of pitch or rosin to a short wooden or stone handle called a mollette. This short handle and wide distribution could lead to a rocking of the blank as it guided over the form, resulting in distortions of shape. Huygens’s improvement made use of an iron pin which acted as a bearing in the center of a piece of wood sitting over the glass. The pin was affixed to a wooden shaft that was suspended from above. This arrangement did not necessitate the use of pitch to attach the lens, and thus avoided fouling the abrasive with fragments of rosin. The technique must have worked well, because Huygens referred to using it into the early 1660s and even dedicated to it several pages in his extensive De Vitris Figurandis…representing work done in the 1670s and 1680s (97 – 98 )

Whatever the fabrica that Spinoza saw and commented on, it most surely employed something of the bâton mechanism. And it is likely that it is at least in part this that Spinoza is commenting on when he says: “experience has taught that with spherical pans, being polished by a free hand is safer and better than any machine”. But the automated potential of Huygens’s machine exceeds this semi-assisted mechanism, for there is a long history of Huygens’s conceptual experimentation with a fully automated device which would both hold the glass blank, but also turn and grind it. In these the glass blank and the forming pan apparently spun against each other in opposing directions. Here are several of these prospective machines:

Oeuvres Complètes, XVII (p.303)

 Oeuvres Complètes, XVII (p.304)

As Graham Burnett describes:

They are gear- and belt- driven, imparting both rotary and epicyclic motion to the glass blank, and they are all represented as self-contained boxes out of which lenses would emerge more or less by the turn of the crank. In fact in [the figure from page 303 of OC], it appears that the crank itself was forgotten and had to be added as an afterthought – a pentimento that speaks volumes concerning the preoccupation with excessive of the process (98 )

Burnett’s global point, if I read him right, is that Huygens’ plans for a completely mechanized production of mathematically exact lenses, purged from the human errors of the craftsman, is in the heritage of Descartes own, highly unrealistic schemata for a hyperbolic lens-grinding machine, symptomatic perhaps of a tendency to divorce body from mind. Burnett is quick to point out that Huygens, unlike Descartes, had extensive experience both in grinding lenses, and using them for discovery (for instance his discovery of the moon and rings of Saturn in 1656 is epic), yet the overall point of this tendency in conception holds. And likely it is to this that Spinoza is in some degree responding.

To better conceive of the contrast between whatever state the Huygens machine may have exhibited (in this spectrum of automatizations), and the simple lathe Spinoza may have employed, a juxtaposition of one of Huygens’s drawings a reproduction of a possible Spinoza lathe will serve:

 

 Oeuvres Complètes, XVII (p.302)

From the Middelburg 400th Anniversary of the Telescope Exhibit, design from Manzini’s “L’occhiale all’occhio, dioptrica pratica”  (1660), circa 1614.

From Manzini

One can immediately see the kind of condensed block mechanism that Huygens would like to have built, and to some degree had built, and the kind of traditional lathe that Spinoza may have used. In fact I have come to strongly suspect that in addition to the simple hand driven lathe depicted above, he likely also used a spring-pole lathe (such as the one in the Rijnsburg museum [here], though this museum piece is not of the period, nor a lens grinding lathe), most likely of the kind Hevelius used (pictured below) the hypothesis discussed here:

Spinoza’s lathe emphasized personal skill, the sensitive hand-eye-machine interface that drew not only on experience and a patient, attentive eye, but also on the particular passed on abrasive recipes and techniques of individual masters. Huygens’s ambition, as was Descartes’ was to transcend the event of crafting, mathematically. That is, with a mathematics that was embodied by the mechanism itself he hoped to simply machine the accuracy. Spinoza’s doubts to whatever fabrica he saw at the Huygens Estate were doubts about removing the “free hand” from the technology. And there is something to this that goes beyond whether this machine or that is at any one moment in history the better machine.

Speculatively: What Spinoza has in mind with the “free hand” is that the human element must be included in any epistemological assemblage. He would no more refuse the mechanized advances in contemporary technology than he would refuse more and more adequate ideas, but he would still look for the “free hand”, the touching point that circulates that knowledge back down to the user, and other men. Technical knowledge still must be human knowledge. The causes of things related to the causes of men. This is what I believe he meant by the fourth stimulation of the “means necessary to attain our end” in the Emendation of the Intellect:

4. To compare this result [the extent to which things can and cannot be acted upon] with the nature and power of man.

There is no doubt that Huygens was on the right track. His mentality was to lead him to a wave theory of light to complement Newton’s spectrum discoveries of the same. In fact, Huygens’s scientific discoveries and inventions are prodigious for the age, but it is good to note that Spinoza in the year of 1665 was fairly close to Huygens, and in many ways Spinoza’s optical and practical knowledge circulated with that of Huygens. That latter would affirm as late as 1668 that Spinoza was in fact right all along about the superiority of small objectives in microscopes, and had marveled at the lens polish that Spinoza was able to achieve through rather craftsman-like means. In reading the objection that Spinoza makes to Huygens’ machine one should understand it at two levels. The first is simply the pragmatic matter of an experienced craftsman who is not intoxicated by technical marvels in their own right. The turning of shiny gears does not make his heart sing. Taking his hand off the lens seems to him one of the last things one would want to do, and it would take a striking result to convince him otherwise, a result which Huygens would not be able to provide. The second level is as vast as the first is earthbound. Spinoza’s notion is that no matter how intricate the device (or the mathematical figure), the meaning of its products, the degrees to which their ideas set us free or not, must relate back to the human being itself, as it finds itself in history. In a sense, Spinoza is looking microscopically beneath, and macroscopically beyond Huygens’s improvements in his letter 32, as a craftsman and a metaphysican.