... Conclusiones aliquot physiologicae de sensibus

continues from previous page: ; that, however, is the animal spirit, elaborated in a certain way from the vital spirit, brought from the heart to the brain through the carotid arteries.

X.
For some time now, that opinion of Aristotle regarding the seat of the soul and the animal spirit, and the origin of the nerves in the heart, has been rightly expelled from the schools of physicians, as it is everywhere, so also in book 3, On the Parts of Animals, chapter 4.

XI.
For the brain is the domicile of the Soul, in which that contained animal spirit has an attached faculty which holds the status of an organ, by the benefit of which the senses are perfected.

XII.
The external senses indeed operate when that faculty is transmitted into the sensory nerves, through which they conceive the images of external things in their proper instruments; the internal senses, however, operate when those same [images] are brought to them.

XIII.
It is not, however, without controversy whether the faculties of the external senses are innate to the sensory organs, such as the power of seeing in the eye, etc., or rather in the brain.

XIV.
But our Hippocrates seems to have determined this correctly in two Aphorisms: "Those who feel pain in some part of the body, and for the most part do not feel pain, in them the mind is sick," book 2, Aph. 6. And: "When two pains exist at the same time but not in the same place, the more vehement one obscures the other," ibid. 46; for a greater pain attracts sensation and thought.

XV.
Sensation, therefore, can be called the perception, or to aisthesin the sensation, of sensible forms.

XVI.
Galen, in his first book On Affected Parts, teaches, along with Aristotle (book 2, On the Soul, context 51; and book 7, Physics, context 12), that the sense is not properly acted upon or varied by the sensible object or by the medium, but only in a certain manner.

XVII.
Some, however, except Taste and Touch; others, on the contrary, [argue about] the sense