And since we have said that the animal spirits are not only cause of movement, but also of sense, it will be necessary here to treat of the senses, of which some are particular and others common, some exterior, which are seen from outside, and others interior,
which are not seen. And because the virtue of the exterior ones depends on the interior ones, we shall treat first of these. The exterior and particular ones are the five that we all know, which go to end in a common sense that we have in the first part of the brains. For from here are born the nerves, through which pass the spirits that give virtue of sensing to these five senses, and by these same nerves they send the species and images of the things that they sensed to this common sense, and give it news of what they perceived, and in this coin they pay the benefit received, serving as servants and messengers to their lord, giving him account of what passes outside. And this is, as the philosophers say, the beginning of all our knowledge, which begins from these senses.
After this common sense, a little farther on there is another hollow, which we call the imagination, which receives all these same images, and retains and keeps them faithfully, because the common sense is in a very tender part of the brains, and for that reason is disposed so that these images may be impressed in it, but it is not so for retaining and conserving them because of its much softness. And for this reason the Creator provided another little ventricle in another part of the brains more hard, which follows after this, which receives all these images and keeps them, and for that reason is called imaginative. With which power, because it is organic and corporeal, our adversary many times makes cruel war on us, painting things to us sometimes most beautiful, and sometimes most ugly, as fulfills his malice, and the one and the other we see in Amnon, son of David, toward his sister Tamar.
After this power there is a little farther on, in the same brains, another little ventricle, which in the brutes is called estimative, and in men, because this faculty is more excellent in them, is called cogitative, which is a power more spiritual than the past ones, and for that reason can conceive things that have neither figure nor body. And thus the sheep, seeing the wolf, conceives enmity, and on the contrary friendship seeing the mastiff. And the weak and unarmed birds do the same, when they see the birds of prey, because friendship or enmity are things that have neither figure nor body, and of this faculty the Creator provided all birds and animals for their conservation and defense.
Lastly, in the last part of the brains that are in the occiput, he placed the memory, which is more proper to man than to the brutes, although some participate in it, as we see in the dog, which hides the bread, and afterward remembers where it put it, and returns for it; and the fox does the same, which after it has fed itself on the blood of the hens that it killed, makes a hole in the earth, and hides them there, and returns to eat of them. Also of the lion it is written that it has memory of benefits and gratifies them, and also of injuries received, and avenges them. But in man this memory is more perfect and more universal, as we shall presently declare, if first we put a palpable example, so that the origin of the knowledge of these four interior senses may be understood. I say, then, that just as the Creator placed in the tongue this faculty of feeling the flavors of foods, and distinguishing between the sweet and the bitter and between the savory and the insipid (which no other parts of all our body feel), so the same artificer, with the omnipotence of his virtue, could impress and did impress these aforesaid faculties in these four parts alone of our brains, and not in others.
But let us return to the memory, which is a singular benefit of God, and even a great miracle of nature. And I say benefit, because it is depositary of the sciences, since only that which we remember do we know. It is faithful helper of prudence, which by the memory of past things understands the stopping place and success of present and future things. It is conserver of experiences, which serve no less for science than for prudence. It is mother of eloquence, and the one that teaches us to speak, keeping within itself the words of things with which we explain our concepts and give ourselves to be understood, wherefore the teachers of speaking, who are the rhetoricians, put memory as the fifth part of their office. It itself enables us for all the arts and for all the sciences, keeping and retaining in itself the rules and precepts of them, without which reading books or attending schools would be to gather water, as they say, in a sieve, without which arts and disciplines human life would be life of barbarians or of fierce beasts. And over all this it serves to make men grateful to God, bringing to their memory the benefits received, to give him thanks for them. Then by all this is seen what we owe to the Creator for this singular benefit.
But the miracle of this power is no less than the benefit, because for men to remember a history, where the things go chained and have dependence one on another, is not much, but to see that a boy takes by heart one hundred Greek or Latin words, whose signification he does not understand, and which have no dependence one on another and that, repeating them in the memory seven or eight times, in such manner they settle and remain in it that, if it comes to hand, they are there kept until old age, and that every time he should wish to repeat them they come out from that hollow where they were, and the memory faithfully returns the deposit that was entrusted to it, is this not a thing of great admiration? Then what shall I say of those who know the four languages: Latin, Greek, Hebrew, and Chaldean, where it is necessary that he who has to understand and speak them have in the memory so much infinity of words as there is in all these languages, and that all of them serve him the times he should wish to speak in them? But what shall we say of some admirable memories, such as was that of the blessed pontiff, Saint Anthony, of whom it is written that, being of the age of fifteen years, he took into memory the whole Decretum in the space of one year? What of the memory of Mithridates, king of Pontus, of whom it is written that he knew twenty-two languages? Then who was powerful to impress in that so small little cell of the brains such ability, such capacity, and so great a space, where so many differences of words could distinctly know without the one being confused with the others? Who was powerful for this, except that Lord who thus in this as in other infinite things wished to show us the greatness of his omnipotence and magnificence? And with all this we men are such, that we neither know how to esteem this miracle, nor to give thanks to the Creator for this benefit.