De causis curatricibus Theses Progymnasticae

Nature: the Soul, I say, insofar as it exercises its nutritive and generative power and office through the service and ministry of innate heat, and not by any other essence really distinct from it.

LXII.
But the Galenists, insofar as they contemplate man philosophically, follow Plato rather than the Peripatetics. Indeed, after they saw three principal different actions being performed in the body in the same three principal and different parts, they surmised that they also proceeded from different principles; and thus, they established three souls in man, or as many substantial parts or faculties, with the names, properties, and series enumerated above.

LXIII.
However, insofar as they contain themselves within their own limits, they never descend to the consideration of the principal efficient—that is, the Soul—nor do they have any need to descend (although they hardly ignore or deny it). Instead, they stop at the proximate causes (that is, the instruments) of the actions, as if at their proper ends.

LXIV.
For since they acknowledge only the body of man as their subject (since it alone can suffer the affections of health and disease, of which they profess the preservation of the former and the expulsion of the latter), they consider only its substance and nature.

LXV.
Because, therefore, they are engaged only with corporeal, material, and sensible things, they are content to know only those things offered to the senses (whence physicians are commonly called "sensitive artisans"). That which lies hidden—perceived not by sense but only by the intellect and the artificial investigation of reason, and which is moreover impassible and by that reason not subject to the power of Art (that is, the Form or Soul)—they dismiss.

LXVI.
In this mode of contemplation, after they had manifestly grasped that when innate heat and the temperament of the body's parts are damaged, the actions and life itself are also damaged; and when that same heat and temperament are safe, the actions and life remain unharmed: they therefore established heat and temperament—that is, what philosophers call the instrument—as the efficient causes of the body's actions and life, or even Nature itself, or indeed sometimes (as can be seen in Galen) the Soul itself; and they rightly thought that their Art was properly occupied with the knowledge and protection of these.

LXVII.
Although in philosophy things ought to be judged not according to how they appear to the sense, but as they exist really and according to their essence, this mode of considering did not lead them away from the truth, and it was by no means insufficient for them to fulfill all the duties of their office and to attain their defined end.

LXVIII.
For that reason, it happened that they confined their speculation to the subject and the corporeal instruments, and to produce it to that further efficient