Commentary Aristotle Metaphysics
6. In this part, it is clear that he gives two reasons why sight is superior to the other senses in knowing.
The first is that it knows in a more perfect way, and this belongs to it because it is the most spiritual of all the senses. For the more immaterial a power is, the more perfectly it knows. And evidently sight is a more immaterial sense if we consider the modification produced in it by its object. All other sensible objects change both the organ and medium of a sense by a material modification: for example, the object of touch by heating and cooling, the object of taste by affecting the organ of taste with some flavor through the medium of saliva, the object of hearing by means of motion in the body, and the object of smell by means of the evaporation of vaporous elements. But the object of sight changes the organ and medium of sight only by a spiritual modification. Neither the pupil of the eye nor the air becomes colored, but they only receive the form of color in a spiritual mode of being. Therefore, because actual sensation consists in the actual modification of a sense by its object, it is evident that that sense which is changed in a more immaterial and spiritual way is more spiritual in its operation. Hence sight judges about sensible objects in a more certain and perfect way than the other senses do.
7. The other reason which he gives for the superiority of sight is that it gives us more information about things. This is attributable to the nature of its object, for touch and taste, and likewise smell and hearing, perceive those accidents by which lower bodies are distinguished from higher ones. But sight perceives those accidents that lower bodies have in common with higher ones. For a thing is actually visible by means of light, which is common both to lower and higher bodies, as is said in On the Soul 2. Hence the celestial bodies are perceptible only by means of sight.
8. There is also another reason. Sight informs us of many differences between things, for we seem to know sensible things best by means of sight and touch, but especially by means of sight. The reason for this can be drawn from the fact that the other three senses perceive those accidents that in a way flow from a sensible body and do not remain in it. Thus sound comes from a sensible body inasmuch as it flows away from it and does not remain in it. The same thing is true of the evaporation of volatile elements, with which and by which odor is diffused. But sight and touch perceive those accidents that remain in sensible bodies, such as color, warmth, and coldness. Hence the judgment of sight and touch is extended to things themselves, whereas the judgment of hearing and smell is extended to those accidents that flow from things and not to things themselves. It is for this reason that figure and size and the like, by which a sensible being itself is disposed, are perceived more by sight and touch than by the other senses. And they are perceived more by sight than by touch, both because sight knows more efficaciously, as has been pointed out, and also because quantity and those [accidents] which naturally follow from it (which are seen to be the common sensibles) are more closely related to the object of sight than to that of touch. This is clear from the fact that the object of sight belongs in some degree to every body having some quantity, whereas the object of touch does not.
9. Animals by nature, then. Here he considers the hierarchy in knowledge.
He first does this with respect to brute animals;
and then, with respect to men, at thus other animals.
With respect to brute animals he mentions first what all animals have in common;
second, that by which they differ and surpass one another, at now in some animals.
Now all animals are alike in the respect that they possess by nature the power of sensation. For an animal is an animal by reason of the fact that it has a sentient soul, which is the nature of an animal in the sense in which the distinctive form of each thing is its nature. But even though all animals are naturally endowed with sensory power, not all animals have all the senses, but only perfect animals. All have the sense of touch, for this sense in a way is the basis of all the other senses. However, not all have the sense of sight, because this sense knows in a more perfect way than all the other senses. But touch is more necessary, for it perceives the elements of which an animal is composed (the hot, cold, moist and dry). Hence, just as sight knows in a more perfect way than the other senses, in a similar way touch is more necessary inasmuch as it is the first to exist in the process of generation. For those things that are more perfect according to this process come later in the development of the individual, which is moved from a state of imperfection to one of perfection.
10. Now in some animals. Here he indicates the different kinds and three levels of knowing found among brute animals. For there are certain animals that have sensation, although they do not have memory, which comes from sensation. For memory accompanies imagination, which is a movement caused by the senses in their act of sensing, as we find in On the Soul 2. But in some animals imagination does not accompany sensation, and therefore memory cannot exist in them. This is found verified in imperfect animals, which are incapable of local motion, such as shellfish. Since sensory cognition enables animals to make provision for the necessities of life and to perform their characteristic operations, those animals that move toward something at a distance by means of local motion must have memory. If the anticipated goal by which they are induced to move did not remain in them through memory, they could not continue to move toward the intended goal which they pursue. But in the case of immobile animals, the reception of a present sensible quality is sufficient for them to perform their characteristic operations, since they do not move toward anything at a distance. Hence these animals have an indefinite movement as a result of vague imagination alone, as is said in On the Soul 3.
11. Again, from the fact that some animals have memory and some do not, it follows that some are prudent and some not. For, since prudence makes provision for the future from memory of the past (hence Cicero makes memory, understanding, and foresight parts of prudence in Rhetoric 2), prudence cannot be had by those animals that lack memory. Now those animals that have memory can have some prudence, although prudence has one meaning in the case of brute animals and another in the case of man. Men are prudent inasmuch as they deliberate rationally about what they ought to do. Hence Ethics 6 says that prudence is a rationally regulated plan of things to be done. But the judgment about things to be done that is not a result of any rational deliberation, but of some natural instinct, is called prudence in other animals. Hence in other animals prudence is a natural estimate about the pursuit of what is fitting and the avoidance of what is harmful, as a lamb follows its mother and runs away from a wolf.
12. But among those animals that have memory, some have hearing and some do not. And all those that cannot hear (as the bee or any other such animal) are still incapable of being taught even though they have prudence; that is, they cannot be habituated to the doing or avoiding of something through someone else’s instruction, because such instruction is received chiefly by means of hearing. Hence in On Sense and Sense Perception it is stated that hearing is the sense by which we receive instruction. Furthermore, the statement that bees do not have hearing is not opposed in any way to the observation that they are frightened by certain sounds. For just as a very loud sound kills an animal and splits wood, as is evident in the case of thunder, not because of the sound but because of the violent motion of the air in which the sound is present, in a similar fashion those animals that lack hearing can be frightened by the sounding air even though they have no perception of sound. However, those animals that have both memory and hearing can be both prudent and teachable.
13. It is evident, then, that there are three levels of knowing in animals.
The first level is that had by animals that have neither hearing nor memory, which are therefore neither capable of being taught nor of being prudent.
The second level is that of animals that have memory but are unable to hear, which are therefore prudent but incapable of being taught.
The third level is that of animals that have both of these faculties, and which are therefore prudent and capable of being taught.
Moreover, there cannot be a fourth level, so that there would be an animal that had hearing but lacked memory. For those senses that perceive their sensible objects by means of an external medium—and hearing is one of these—are found only in animals that have locomotion and which cannot do without memory, as has been pointed out.
14. Thus other animals. Here he explains the levels of human knowing. In regard to this he does two things.
First, he explains how human knowing surpasses the knowing of the abovementioned animals.
Second, he shows how human knowing is divided into different levels, at now in men.