  “This [separate substance] will therefore be the spiritus, which took its origin from the semen, as we will explain elsewhere (and it is to be found in all things made from semen, namely those which are white and bloodless, with the exception of the bones and similar things); and only the spirit is what perceives in the animal, and moves sometimes with the whole body, sometimes with single parts thereof, and solely governs the whole animal. That is to say, it performs those actions which, according to the concurring opinion of all, are typical of the soul.” (Vol. II, p. 208).