Animals feel pain - so much is obvious.

But René Descartes didn't think so.

In fact, the man who has been called the Father of Modern Philosophy thought there was no more to the yelps and cries of a suffering animal than the squeaks and groans of an unoiled hinge, and (for the purposes of science) he was even rumoured to have dissected living dogs and nailed cats to trees. For, he reasoned, we wouldn't worry about the "feelings" of a watch or a clock, no matter what noises it made.

Descartes's views on animals now seem callous and outdated, and we might readily consign them to the dustbin of the history of ideas - except for the fact that many people still share them. For curiously, Descartes's views have formed the basis for modern developments in computing and artificial intelligence - from which point of view, we are all just machines.

Written in an engaging and humorous style, this short book investigates the roots of this philosophy, exploring the connections between Descartes's view of animals, AI, and the persisting puzzle of consciousness.