Key Arguments

• He reiterates that "without touch, though, no other perceptual capacity can be present," reinforcing its foundational status relative to the other senses.
• He infers that the organ of touch "is composed neither of earth nor of any of the other elements", marking it off as a special mixed organ appropriate to animal life.
• He draws the explicit conclusion: "It is evident, accordingly, that this is the only perceptual capacity with the loss of which an animal must die," making touch uniquely life-critical.
• He underscores that only animals possess touch and that nothing non‑animal can have it: "For | 435 b 5 | it is not possible for anything to have this if it is not an animal," so touch both marks and confines the class of animals.
• He adds that "nor is there any besides it that something must have to be an animal", indicating that no other single sense is necessary in the same way.
• He ties this to his earlier demonstrations: "For it has been shown that without touch it is impossible for an animal to exist," appealing to prior arguments that every animal must be tangible and have a touch-organ.

Source Quotes

For touch is as it were a mean between all tangible objects, and its perceptual organ is receptive of not only the differentiae (diaphora) of earth but also of heat and cold and all the other tangibles. 446 And this is why we do not perceive with our bones, hair, or other such parts, namely, that they are composed of earth. | 435 a 25 | It is also because of this that plants have no perceptual capacity at all, namely, that they are composed of earth. | 435 b 1 | Without touch, though, no other perceptual capacity can be present, and its perceptual organ is composed neither of earth nor of any of the other elements. It is evident, accordingly, that this is the only perceptual capacity with the loss of which an animal must die.

446 And this is why we do not perceive with our bones, hair, or other such parts, namely, that they are composed of earth. | 435 a 25 | It is also because of this that plants have no perceptual capacity at all, namely, that they are composed of earth. | 435 b 1 | Without touch, though, no other perceptual capacity can be present, and its perceptual organ is composed neither of earth nor of any of the other elements. It is evident, accordingly, that this is the only perceptual capacity with the loss of which an animal must die. For | 435 b 5 | it is not possible for anything to have this if it is not an animal, nor is there any besides it that something must have to be an animal.

It is evident, accordingly, that this is the only perceptual capacity with the loss of which an animal must die. For | 435 b 5 | it is not possible for anything to have this if it is not an animal, nor is there any besides it that something must have to be an animal. And this is why the other perceptible objects (for example, color, sound, and odor) do not in excess destroy the animal but only the perceptual organs—except coincidentally, such as when a push or a blow takes place at the same time as the sound); | 435 b 10 | and by dint of visible objects or an odor other things are caused to move which destroy by touch.

447 But excess in tangible objects—for example, hot ones, cold ones, or hard ones—does away with the animal. For excess in every perceptible object does away with the perceptual organ, | 435 b 15 | so that in the case of tangible objects it does so to touch, which is what the animal is defined by. For it has been shown that without touch it is impossible for an animal to exist.

For excess in every perceptible object does away with the perceptual organ, | 435 b 15 | so that in the case of tangible objects it does so to touch, which is what the animal is defined by. For it has been shown that without touch it is impossible for an animal to exist. That is why excess in tangible objects destroys not only the perceptual organ but also the animal, because this is the only one that it must have.

Key Concepts

• Without touch, though, no other perceptual capacity can be present, and its perceptual organ is composed neither of earth nor of any of the other elements.
• It is evident, accordingly, that this is the only perceptual capacity with the loss of which an animal must die.
• For | 435 b 5 | it is not possible for anything to have this if it is not an animal, nor is there any besides it that something must have to be an animal.
• For excess in every perceptible object does away with the perceptual organ, | 435 b 15 | so that in the case of tangible objects it does so to touch, which is what the animal is defined by.
• For it has been shown that without touch it is impossible for an animal to exist.

Context

Middle of III.13 (around 435a25–435b7, 435b15), where Aristotle elevates touch above the other senses by arguing it is both uniquely possessed by animals and uniquely required for their existence, so that losing touch means ceasing to be an animal.