In 1637 René Descartes declares animals to be artificial machines. For Gwendolin Kirchhoff vivisection is the key concept for diagnosing the consequence of the Cartesian animal-machine picture as ethical catastrophe. No consciousness, no sensation, no interiority. What a dog utters when one cuts it open is, on this view, the same as the squeaking of a wheelwork. Less than thirty years later vivisection is common practice at European universities. The connection between the philosophical sentence and the cut-open animal is no chance coincidence. It is the logic of an ontological decision unfolding its consequences.
#The definition makes the intervention possible
Gwendolin Kirchhoff brought this connection to a formula in the Everlast AI debate (2026): in the moment we define something as machine, we justify destructive interventions, loss of empathy and an arbitrary exploitation of what we have so defined (cf. Gwendolin Kirchhoff, Everlast AI Debate, 2026, 79:05–79:50).
The decisive point is not the surgical act. Vivisection existed before Descartes and would have continued without him. Joscha Bach pointed out rightly in the same conversation: it is not Descartes who invented vivisection (cf. Joscha Bach, Everlast AI Debate, 2026, 83:26). But Kirchhoff’s argument aims not at historical causality but at ontological legitimation. Cruelty has always existed. But only the philosophical definition of the animal as machine transforms cruelty into methodical indifference. Whoever grasps a suffering being as mechanism no longer needs a bad conscience — they have a paradigm.
Descartes’ move consisted in separating the res cogitans (thinking substance) from the res extensa (extended substance) so radically that everything non-human fell on the side of pure extension. What does not possess thinking substance is mechanism. What is mechanism has no inner life. What has no inner life cannot suffer. The conclusion is formally correct; the premise is the problem.
#Aristotle’s legacy, misread
Kirchhoff named the Aristotelian background in the debate: Descartes’ animal-machine thesis is one of the first acts, ultimately an Aristotelian point, emerging from a particular peripatetic line of argument (cf. Gwendolin Kirchhoff, Everlast AI Debate, 2026, 79:08). This is a precise diagnosis. Aristotle had certainly granted animals a soul, the psyche aisthetike, the sensing soul. But he had also introduced a ranking: vegetative, animal, human. What in Aristotle was a gradation of complexity became in Scholasticism a boundary between the ensouled and the unensouled. Descartes radicalised this boundary by simply striking the animal soul.
Christof Koch notes in The Feeling of Life Itself (2019) that this Cartesian separation continues to act into modern neuroscience. The implicit assumption that only human consciousness is consciousness in the full sense is the distant echo of a decision from the seventeenth century (cf. Koch, 2019).
#What dis-ensoulment produces in practice
The consequence of the definition is not limited to animals. Kirchhoff drew the line in the debate to colonial history and pointed to the general pattern: certain forms of thought colonise. They are nameable forms of thought, for example our money system, which did not exist among many peoples of the world (cf. Gwendolin Kirchhoff, Everlast AI Debate, 2026, 79:50–80:06). The structure is the same: what is defined as unconscious may be exploited. What counts as mere resource needs no consideration. Vivisection is the precedent, but the pattern operates in every exploitation that hides behind a paradigm.
Jochen Kirchhoff put the deeper connection into a sentence: the machine is an artefact, dis-ensouled. Today’s natural science sees nature only from outside, and what it sees from outside it can calculate. But the inside, the inner perspective, is bracketed out. That is ultimately a catastrophe (cf. Jochen Kirchhoff, Was die Erde will, 1998). Vivisection makes this catastrophe literally visible: an animal is opened up to study its interior, and through precisely this opening its actual inner life is destroyed. The organ becomes visible; the sensation is annihilated.
#The reverse repetition in the AI debate
Descartes declared the living a machine. Computationalism declares the machine potentially living. Both times the difference between the mechanical and the organic is levelled, but in opposite direction. Lewis Mumford described this procedure in 1967 in The Myth of the Machine as the central setting of the modern era: the autonomisation of the principle of the calculating machine, which is only the externalisation of an already-completed imprisonment of the human being in a section of itself, namely abstract rationality (cf. Mumford, 1967).
If you think the parallel through, a disquieting symmetry shows itself. In the seventeenth century interiority was denied to the animal, and that allowed vivisection. In the twenty-first century interiority is ascribed to the machine, and that allows the notion that human functions are replaceable. Both moves operate with the same confusion: the analogy between the living and the mechanical is taken for an ontological identity. What begins as heuristic model becomes a claim about reality, and from the claim about reality follow interventions.
#The question of the criterion
What makes vivisection so philosophically illuminating is the question it forces: by what do you recognise that something suffers? Descartes had an answer: only what thinks senses. Bach gave another in the debate: the dog suffers because it is a quite similar machine to me; it has a quite similar consciousness. There is a continuum between me and the dog (cf. Joscha Bach, Everlast AI Debate, 2026, 82:02–82:07). The empathy judgement remains for Bach normative but not ontologically grounded: he rejects animal experiments but holds that the word machine applies to the dog.
Kirchhoff’s position is another. Consciousness is not an emergent control process that one grades and ascribes to various systems. Consciousness is a constitutive property, an ontological foundation of the world that underlies all living beings insofar as they are living beings (cf. Gwendolin Kirchhoff, Everlast AI Debate, 2026, 80:06). The dualism that splits consciousness from the body first creates the problem that reductionism then wants to solve. And vivisection is the historical document of this problem: a philosophy that executes its own outcome on a living body.
Schelling formulated the counter-position in the Ideas for a Philosophy of Nature (1797): the inorganic is only the negated organism, the dead only the suppressed life. There is nothing absolutely dead. If that holds, then vivisection is not only cruel but ontologically blind. It cuts into something whose nature it does not grasp, because it has dis-ensouled it definitionally beforehand. In philosophical work this pattern is encountered everywhere a person discovers that the living within them cannot be described as function to be optimised, repaired or replaced. The entries on animism, materialism and computationalism follow the strands of this thought further.
#Sources
Descartes, R. (1641). Meditationes de Prima Philosophia.
Kirchhoff, G. (2026). Everlast AI Debate: Gwendolin Kirchhoff vs. Joscha Bach.
Kirchhoff, J. (1998). Was die Erde will.
Koch, C. (2019). The Feeling of Life Itself: Why Consciousness Is Widespread but Can’t Be Computed.
Mumford, L. (1967). The Myth of the Machine: Technics and Human Development.
Schelling, F. W. J. (1797). Ideen zu einer Philosophie der Natur.