Leftovers / Leibniz’s Syrup of Ipecac

“Leftovers” is a column that investigates the cultural significance of detritus.

There was once a prominent mid-twentieth century British philosopher, bearing the auspicious family name “Wisdom,” who at a certain point in his career—pehaps in a spell of depression, when logical analysis came to seem empty to him—discovered psychoanalysis. Professor Wisdom wrote a book about the eighteenth-century philosopher George Berkeley, a psychobiography of sorts, in which he made the case that the Irish idealist’s rejection of matter is best understood as a vestige of his passage through the anal phase, a sort of delayed grappling with the “non-being” of that dark mass that came out of him in the form of feces.

Now this is just the sort of theory one is trained as an academic philosopher not to propose. It is the sort of theory, one is given to know, that will swiftly land one on one’s ear outside any respectable philosophy department in the English-speaking world. The French, in contrast, are rather more permissive of this sort of unfalsifiable belle-lettrification of the genesis of the dead masters’ ideas. Putting the finishing touches on my book on G. W. Leibniz, on a topic for which most of the secondary literature is, for better or worse, in French, I was delighted recently to come across this gem of Francophone scholarship, which I translate verbatim:

By invoking Leibniz’s meticulousness, his scrupulous character, his tiny handwriting, his taste for endless accumulation of information and of other more tangible goods and, finally, his certain sexual frigidity, an orthodox psychoanalyst would without doubt have made the diagnosis of a fixation or a regression of the libido with the anal phase predominating.

The author adds that “the retrospective psychoanalysis of a person who has been dead for so long amounts to an extremely hazardous enterprise,” but this disclaimer is not enough to prevent the picture the imagined psychoanalyst paints from sticking in our heads. Leibniz, the picture suggests, was in his own way perverted, as is anyone who ever accomplishes anything of note.

I am professionally obligated to erase that picture. Yet the longer I dwell with Leibniz, the more his cramped, obsessive handwriting enters into my dreams, the more my wife has to insist on quotas for the number of times per day I’m permitted to mention his name, the more I find myself entertaining psychogenetic theories of my own. Much of Leibniz’s philosophy, I have come to believe, is motivated by a preoccupation with the simultaneous instability and inescapability of the body, or, more to the point, of his body. His body is in constant flux, like a river or a fountain, yet he has no choice but to flow along with it.

Some will recognize in the image of the river an allusion to Leibniz’s metaphysics of corporeal substance: every monad is the active, perceiving center of an infinitely complex organic body, and no monad can be entirely disembodied, since embodiment is in metaphysical rigor nothing but the phenomenal consequence of the monad’s confused perception. No monad, moreover, can ever come into or go out of existence except by God’s miraculous intervention since, though always embodied, in itself it is perfectly simple, and therefore logically insusceptible to dismantling. So monads exist eternally in a bodily form, yet not, as certain mystical traditions had supposed, eternally attached to some particular chunk of matter. Rather, they change their matter constantly, just as a wave traveling over the surface of the ocean is constantly in the process of changing the water that constitutes it. The monad that is the soul is always embodied, yet its body is always slipping away from it. Leibniz’s soul is embodied, yet he doesn’t have the comfort of having a body.

Even those familiar with Leibniz, however, will probably not know that throughout his career he shows a particular interest in discovering new methods of probing into the inner workings of men and dogs and frogs. “We need to find ways to penetrate ever further into the innermost part of a living being,” he writes in an unpublished manuscript of 1671. One way of doing this, he proposes, is by further developing the science of anesthesia: “We must find a way to put a person into a deep sleep, in order not to harm him, to the extent that he would feel nothing, and could be easily awakened from this state.” Should this not be possible, there are fortunately also animals, on which experiments can be made without concern for their pain. “We must conduct innumerable anatomical studies on animals, living as well as dead,” Leibniz writes, complaining that veterinary science has been principally based on equine diseases, since the cure of these is of immediate economic relevance. We can learn not just about anatomy from animals, but also about pathology and the stages of development of diseases, since with animals, unlike humans, “we can cut them open and examine them when and how we please.”

Autopsy on human beings is also useful for penetrating into the body, even if we do not have the convenience of being permitted to perform it while they are still alive. Leibniz further hopes that a flesh-eating liquid might soon be discovered that would leave the veins and arteries intact, the better to study them. What is desired is greater knowledge of the living human being, but the only two paths toward it are the living animal or the dead human, and the hope is that these two together might enable us to converge upon an adequately clear picture of the true subject of interest. To this end, all opportunities should be taken to study bodily excrescences such as sweat, blood, urine, saliva, and even breath, which might, Leibniz thinks, be best examined when reduced to a solid state.

Leibniz’s persistent aim is to know the inner through the outer: “We must namely find, by the use of reason, the communications of the external members with the internal viscera, so that it will be possible to do a great deal already through external treatments.” He believes, for example, that the condition of the hair, its texture and color, can tell us a good deal about a person’s constitution and health. Traditional forms of reading from external signs, such as the shape of the cranium or the nose, are of course rejected, as it is only what truly emerges from within—what is pushed out from the invisible part of the body and becomes visible—that is diagnostically useful. In contrast, physiognomy as traditionally practiced can tell us nothing about the current, changeable state of a person, since the features that it studies are permanent and coeval with that person: “From the figure of the hair of a man all sorts of useful conclusions may be drawn with certainty. Of the nose and other parts I do not wish to say.”

One would not expect to learn much about a philosopher’s broader concerns from his preoccupation with vomit, yet here, as elsewhere, Leibniz surprises us. Emetics are a longstanding interest for him, and in a 1695 text written for the German Leopoldine Academy, Leibniz lays claim to the discovery that the Brazilian ipecacuanha root, which we know better today in the form of “syrup of ipecac,” works not just as a remedy for dysentery (in France, Helvetius had used it to cure the Sun King’s bad case of the runs twenty years earlier), but also as an emetic, a diuretic, and a diaphoretic. In the early 1670s, Leibniz had dreamed of discovering new ways of bringing the inside of the body out at will, and a quarter of a century later he finds the very potion to make this dream come true.

Leibniz promotes not only experimentation on living animals and dead humans, but also on the self. He believes that bloodletting can be beneficial in some cases, but “it is much more often bad and damaging.” He adds: “I only had my own blood let one time, and this just out of curiosity when I was in very good health.” And he advocates not just self-experimentation and self-diagnosis, but also self-treatment. He writes in 1676, at the age of thirty, that “when one begins to be seized by gout, or to detect it, one must make incisions or scarifications at every new moon, as close to the true time of the new moon as possible, on the pad of the toe above where one begins to feel or to detect the affliction.” Forty years later, in 1716, Leibniz would die of complications from the self-treatment of gout, having built a wooden clamp to cut off circulation to an afflicted foot. It is not known whether at that time he was practicing incisions as well.

Two years prior, in his famous Monadology, a sort of précis of his mature philosophical system, Leibniz wrote: “All bodies are in a perpetual flux like rivers, and parts are entering into them and passing out of them continually.” It is precisely this capacity to endure throughout the flux that wins for the human being, together with his body, the status of true substance as opposed to mere aggregate. The corporeal substance is what is in constant communication with its environment, what has its being only through its environment, to the extent that it takes in material from its environment and transforms that material into itself. Leibniz has saved the body from the mere contingent association with the immortal soul that Descartes had reserved for it, by showing that the impermanence of its parts need not amount to the unreality of the whole. The leeches sucking his blood, the incisions in his toes, confirmed as much.

Richard Wollheim, who more than anyone made me, when I was young, want to become a philosopher, wrote in his memoir, Germs, of his early childhood experience learning to use toilet paper: “It is what I think of when I hear moral philosophers discuss responsibility.” If the particular mechanisms and stages of psychoanalysis have by now been discredited, this does not mean that it is no longer true that human beings, including moral philosophers, first come to gain their most basic orientation in the world through their experience of their bodies, and that the abstractions they manage to arrive at much later, in adulthood, are not replacements for these primary experiences, but only late-coming outcroppings of them. Wollheim’s genius consisted in his mastery of the abstract language of adult philosophy, together with his ability to translate this language back to bear on the sort of entities—embodied, desiring, eating, and excreting ones—that philosophy is in fact about (whatever else it might pretend to be about, e.g., angels, God, disembodied minds, or minds only contingently wrapped up with bodies).

I once had a precocious and overconfident student, who preferred Levinas and Derrida and other mystifiers of youth, and who, when presented with a summary of Daniel Dennett’s austere explanation of consciousness, exclaimed: “He’s just, like, working out his issues.” She may have been right, but I wouldn’t claim to have any knowledge of what those issues might be simply from the content of the theory. No, one needs to go the other way, from the explicit elaboration of the personal issues to the content of the theory. Thanks to Leibniz’s severe graphomania, this is to some extent possible, once one has deciphered his cramped and anal handwriting.

What about his frigidity? Did Leibniz really fill up every square millimeter of his manuscripts with dense text only to compensate for the great absence of any “love life”? Of course, no decent seventeenth-century philosopher was married. The preferred form of love for a man who had chosen the contemplative life was seraphic: clearly erotic, and clearly heterosexual, but not defined by consummation. This is what Henry More enjoyed with the married Lady Anne Conway, and what sustained John Locke in his decades-long cohabitation at a country estate with the married Lady Damaris Masham, whose husband was an absent and indifferent Member of Parliament in London. And it is what characterizes the deepest love Leibniz experienced in his life, with the very married Queen Sophie Charlotte of Prussia. As with our effort to understand the medieval institution of same-sex marriage between “blood brothers,” who often requested that after death they be buried in the same grave in an eternal embrace, the question “Yes, but were they, you know, doing it?” does not really get to the heart of the matter. Whether they were or not, the era of accounting for our erotic impulses in terms of our orifices had not yet begun, so it is not at all surprising that what drips from the pages of the correspondences between these men and women is just love, and not the fluids thought in our strangely Galenic era to be charged with it.

No, Leibniz saved his reflections on fluids for his more private, less courtly, less charming writings, for his auto-diagnoses and his correspondences with medical men. In 1715, Leibniz boasts to his friend Schelhammer that, while Louis XIV might have given Helvetius monopoly rights for the use of ipecacuanha to stop diarrhea, it was he, the great Leibniz, who discovered that it could be used not just to stop a king up, but also to keep his juices flowing. Leibniz is old when he writes this, twenty years after the initial discovery, and by now he knows he is not long for this world. But he draws comfort from this claim to a legacy. He has discovered the perfect emetic. The psychobiographical temptation would have a Leibniz scholar trying to trace the metaphysical innovation of the flux of corporeal substance back to his pharmaceutical preoccupation with coaxing out, as Henry Miller would later say, “everything that flows.” And from there the scholar might go further still, back to the sort of thing Wollheim used to think about whenever he heard moral philosophers talk about responsibility. But I certainly am not going to try. I am a philosopher, and not at all qualified.