Mind is uniform, and is just as good in animals as in man. Man’s apparent superiority is due to the fact that he has hands
 Bertrand Russell, A History of Western Philosophy (1945). copy citation

Context

“Mind is the source of all motion. It causes a rotation, which is gradually spreading throughout the world, and is causing the lightest things to go to the circumference, and the heaviest to fall towards the centre. Mind is uniform, and is just as good in animals as in man. Man’s apparent superiority is due to the fact that he has hands; all seeming differences of intelligence are really due to bodily differences. Both Aristotle and the Platonic Socrates complain that Anaxagoras, after introducing mind, makes very little use of it.” source