Govert Bidloo’s 1698 Reference to a Spinoza Microscope

Dutch Republic Stadtholder and King of England, William III

No Second Spinoza Scope

For those that have been following my thought process and research, for a brief moment I believed we may have found another user of a Spinoza microscope, Govert Bidloo in a 1698 open letter to van Leeuwenhoek on the nature of the flatworm parasite F. hepatica. Unfortunately in looking at the text of the letter yesterday I found it only to be a thorough-going reference to Theodor Kerckring’s own use of a Spinoza microscope in his 1670 Specilegium anatomicum, thus far the only first hand account of observations made with an instrument fashioned by Spinoza’s hand.

But the citation is not without merit. As I pointed out in a previous post, in addition to being professor of Medicine and Anatomy at Leiden University, Bidloo was apparently a republican pamphleteer at the time of great social unrest, and the year before his friend Eric Walten had died in prison as a result of the vehiment side taken in the the Berkker controversy, under the force of the vague charge of being a dangerous Spinozist. In this context, the reference to Spinoza’s microscope in a scentific discourse looking to elucidate the source of diseases of the body seems to be something more than coincidence. Spinoza’s lens, and Kerckring’s observations through it, is positioned by Bidloo between two perceived kinds of diagnostic failure.

Bidloo’s Letter: The Importance of Invading Animalcules and Worms

Here is a lengthy excerpt from Bidloo’s published letter, a passage which follows a record of past observations of possible disease causing worms and animalcules (remember, the distinct etiological sources of human disease are largely unknown at this point in history). The catalogue [only the tail of of which is included here] presents numerous body parts and their reported invaders, the body becoming more and more invested, and it is at the end of this that Kerckring is now cited:

Worms in the legs, the scrotum, and a tumor and bladder full of fulls are mentioned by the Misc. Cur., Years 3 and 4, Obs. 173, and the Year 7, Obs. 16.

In scabies and varioles they are described by Borellus [l.c.], Obs. 72.

In pustules, varioles, and the whole of the body: Rhodius [l.c.], Obsc. 64, Part 3.

A wholly wormy man (alas! that only this disease were somewhat rare!) is reported by the Danes in their [Acta Hafn.[ Part 3, Obs. 11.

Severe symptoms caused by mites are reported by Hildanus [l.c.], Obs. 96, as well as by Benetus [l.c.] in his last Obs., Part 35: “a constant production of worms from infancy to great age. Observations about aged worms of different forms, big and small worms, and other animalcles in all parts of the body are to be found. The dispute, or rather the argument will now have to concern the question of whether these animalcules, which are admitted to be found in the parts of living human bodies, can or cannot be causes of diseases and their symptoms, the more so because, amongst others, TH. KERCKRING, a man who has gained a great reputation in anatomy and medicine, doubts it, when on p. 177 in his [Specilegium anatomicum] Obs. 93 he tries to demonstrate the uncertainty of the opinion that is formed about things in anatomy by means and with the aid of magnifying glasses. He deduces this uncertainty: 1. from the smallness of the sharp centers of the field of view; 2. from the change of color; 3. from the alternate inspection of several parts so that what now seems to be separate in reality is united, nay, united physically. But after having highly commended a certain magnifying glass and its maker, B. Spinoza, he adds these words: by means of this my admirable instrument I saw very wonderful things, viz. that the intestines, the liver, and all the tissue of the other intestines are filled with an infinite number of tiny animalcules; however, a person who considers that a house which is inhabited is clean and bright, but nevertheless wears away through the constant maintenance of those who inhabit it, will tend to doubt whether these animalcules spoil or maintain these parts through their continuous movement.

Although I am not aware what great acceptance, credence, and confidence the unfounded reputations of experience, example, and reports of so-called happenings and so on have received and kept not only among the common people, but unfortunately also among some prominent persons, I will not now oppose or cite any authors who deny or affirm that diseases and their symptoms are caused by worms and other animalcules in the human body. For, to express my opinion both frankly and respectfully, I think that any experience, observation, and example will never by applicable, unless at best somewhere in general, in particular. (translation and notes by J. Jansen, 1972, 53-55)

Animalcules and the Body Politic

But in tension to the full spirit of Kerckring’s reservations about microscopy, and after his own Cartesian warning as to any individual diagnosis achieved through direct observation or experience, Bidloo goes on to express extreme caution to those commonly connecting disease to the states of the blood and bile, instead of thinking about the kinds of damage that can be done the transportation systems of the fluids of the body by animalcules and worms. “Over the former more words, and of the latter, more solid proofs can be produced” (60). Bidloo believes that much of the quackery of blood and bile diagnoses, can be relieved by the direct understanding of the kinds of damage tiny animals can do to the ducts and tissues of the human body, something he imagines the microscope to have revealed the body to be rife with. By his account, animalcules proliferate, bite into organs, pierce and insinuate ducts, ferment the “saps”, and cast their excrement, eggs and young all about. It is the Cartesian dream of understanding the micro-causations of the body, projected upon a image of a body teeming with invaders. (How tempting it must have been for Dutch anatomists to read the heath of the body as dependent upon an essential mechanism of ducts and their transportation of fluids, once the nature of the blood’s circulation was revealed [Harvey 1616, 1628], as the land itself was a canal-rich economy, filled with lucretive waterways in every direction.) 

Put aside by Bidloo is Kerckring’s equanimity of observation though, the inability to tell if the swarms of animals are the sign that the body’s home is florishing in the glow of vivacity, or is being spoiled and overrun by inhabitation. Kerckring’s wider view of the possible symbioses of an organism, in keeping perhaps with Spinoza’s whollistic conception of the interdependency of an expressive mechanism, for Bidloo falls to the sure evidence of minute and proliferate causes of bio-destruction: parasites corroding the canals of the body. This makes an interestingly thought-picture for the personal physician to William III, King of England and Dutch Republic Stadtholder, a man in favor republican values in criticism of the Reformed Chuch. One may suppose that Reason and close observation will guide us into discovering the plethora of worms and animalcules in society, those infesting and injuring the transportation systems and organs of healthy conduct. In citing Spinoza’s lens, and Kerckring’s vision of the teeming animalcules and worms, Bidloo evokes a complex of reason and invasion, a political eco-vision in which the proverbial Scylla (the chicanery of vaguely-diagnosing, self-serving “experts”) is torqued against the threatening Charybdis (a chaos of rabble and infestation), given over to the steerage of social health. Importantly, Spinoza’s lens is juxtaposed, (symptomatically), as a kind of clear crystal manifestion of the narrows through which the two can be negotiated.