Page:The System of Nature.djvu/137

 ordinary: he says the greatest difference he found between the parts of the body of this idiot, and those of wiser men, was, that the plexus of the intercostal nerves, which is the mediator between the brain and the heart, was extremely small, accompanied by a less number of nerves than usual. According to WILLIS, the ape is, of all animals, that which has the largest brain, relatively to his size: he is also, after man, that which has the most intelligence: this is further confirmed, by the name he bears in the soil, to which he is indigenous, which is ourang outang, or the man beast. There is, therefore, every reason to believe that it is entirely in the brain, that consists the difference, that is found not only between man and beasts, but also between the man of wit, and the fool: between the thinking man, and he who is ignorant; between the man of sound understanding, and the madman: a multitude of experience, serves to prove, that those persons who are most accustomed to use their intellectual faculties, have their brain more extended than others: the same has been remarked of watermen, that they have arms much longer than other men.

However this may be, the sensibility of the brain, and all its parts, is a fact: if it be asked, whence comes this property? We shall reply, it is the result of an arrangement, of a combination, peculiar to the animal: it is thus that milk, bread, wine, change themselves in the substance of man, who is a sensible being: this insensible matter becomes sensible, in combining itself with a sensible whole. Some philosophers think that sensibility is a universal quality of matter: in this case, it would be useless to seek from whence this property is derived, as we know it