Descartes’ ability to explain the operation of a body in mechanistic terms – as the great intricate clockwork of God – provided the foundation for a powerful school of physicians in the eighteenth century, and insofar as he showed how ‘life’ worked without the need for ‘soul’ he led the way to a modern scientific understanding of living things.3 But although he won many followers, his rigid dualism – dividing everything so starkly into matter and spirit – and particularly his relegation of animals to the status of insensible lumps of dirt, became the focus of widespread protest all over Europe, notably in England.
People found it hard to accept his contention that animals had no sensation as it contradicted a common-sense view of animal behaviour and made a nonsense of their sentimental attachment to pet dogs. In the intellectual backlash, many philosophers preferred to think that animals had souls and reason rather than concede that they were mere machines.4
The English philosopher Thomas Hobbes agreed with Descartes that animals lacked reason, but he suggested that mind was made of matter and therefore animals could think to some extent.5 Hobbes did not think this accrued to animals any sort of moral protection from humans, even though, like Descartes, he thought the scriptural permission to Noah an insufficient basis for eating them. For Hobbes, might made right: all beings had the right to kill for their own preservation, and humans – by forming alliances with the use of their reason and language – had become powerful enough to kill any animal they chose (while beasts, lacking reason and language, were incapable of entering into the contract of forbearance from conflict enjoyed by human beings).6
The philosophical Duchess of Newcastle, Margaret Cavendish (1624–74), sustained a lengthy correspondence about animals with Descartes and voiced her dissent in her striking poetry:
As if that God made Creatures for Mans meat,
To give them Life, and Sense, for Man to eat;… Making their Stomacks, Graves, which full they fill With murther’d Bodies, that in sport they kill … And that all Creatures for his sake alone, Was made for him, to Tyrannize upon.7
Descartes’ new philosophical view of animals, it seemed to many, was still worse than the disdain fostered by Aristotle and Augustine. Most of the earlier seventeenth-century radical vegetarians, whose main inspiration was the Bible, ignored or remained ignorant of the debate Descartes had triggered.8 But the vegetarian-oriented deists – Blount, Gildon, the Turkish Spy and Simon Tyssot de Patot – identified Descartes as their common enemy, and embraced instead the more conducive animal-friendly philosophy of his rival, Pierre Gassendi.9 If Reason proved that humans had souls, declaimed Mahmut in the Turkish Spy, then the fact that animals were clearly intelligent showed ‘the Brute Animals to have Souls as well as We’; if it did not, he warned, then ‘ ‘tis as easie to defend, That Humane Nature it self is but Matter’.10 (As the traveller to India, John Ovington, had said, even the Pythagoreans and Indians knew that.)11
Descartes felt he had established man’s superiority on the firmest foundations, but because he based it on rational argument rather than Scripture, he opened the door to opposite deductions. Reversing both Descartes’ and Hobbes’ rationale for eating animals, the Turkish Spy concluded that ‘it is little less Injustice to Kill and Eat them, because they cannot speak and converse with us, than it would be for a Cannibal to murder and devour thee or me, because we understood not his Language nor he ours’.12 It was precisely this sort of grotesque logical deduction from Hobbes’ theory of the ‘War of Nature’ that the German philosopher Samuel Freiherr von Pufendorf sought to clear up with his monumental counter-vegetarian article in The Law of Nature and Nations (1672). Pufendorf gave the vegetarians a great deal of space; he was liberally uncritical of Brahmins and other vegetarian peoples and he even endorsed the vegetarians’ argument that meat made people vicious and that humans were better suited to a herbivorous diet. But he explained that men had an indissoluble right to kill because the hostility and competition between them and animals was (in contrast to the occasional conflicts between men) acute and irreparable. Nevertheless, he insisted that the vegetarians were right in so far as ‘foolish Cruelty and Barbarity’ to animals was indisputably reprehensible.13
Members of the public were appalled to hear that Cartesians kicked and stabbed animals to make the point that their cries had no more significance than the squeak of a door. As one horrified witness testified, ‘They administered beatings to dogs with perfect indifference, and made fun of those who pitied the creatures as if they had felt pain.’ Descartes himself was renowned for having cut open his own dog to show exactly how the animal machine operated. Cartesians became indelibly marked as the most inhumane of philosophers. Even Descartes’ contemporary Henry More the Platonist, who admired Descartes to the extent of keeping a portrait of him in his closet, could not accept the doctrine of the beast-machine: ‘my spirit,’ pleaded More to Descartes in a letter, ‘through sensitivity and tenderness, turns not with abhorrence from any of your opinions so much as from that deadly and murderous sentiment … the sharp and cruel blade which in one blow, so to speak, dared to despoil of life and sense practically the whole race of animals, metamorphosing them into marble statues and machines.’ It was better to be a Pythagorean and believe animals had immortal souls than to be so cruel to the creatures, he said.
Descartes, however, urged that far from being cruel, his philosophy was the only just system. If animals could feel pain then man and God were guilty of the most horrendous crimes. Humans (as Augustine explained) deserved to suffer because they had sinned, and had the promise of heaven to look forward to. But innocent animals had never sinned, so how could one justify allowing them to suffer? The only way of excusing mankind’s treatment of animals was to insist that animals were incapable of sensation. ‘And thus,’ announced Descartes, ‘my opinion is not so much cruel to wild beasts as favourable to men, whom it absolves, at least those not bound by the superstition of the Pythagoreans, of any suspicion of crime, however often they may eat or kill animals.’14 Descartes, in his own opinion, had come up with the only viable justification for eating meat. Deny what he said was true, he implied, and morally you would be obliged to take up vegetarianism. As one later vegetarian cynic commented, ‘One must either be a Cartesian, or allow that man is very vile.’