Key Arguments

• We already perceive, by touch, everything that is an affection of the tangible qua tangible, so nothing in the domain of the tangible is left for a new sense: 'if even as things stand we have perception of everything for which touch is the perceptual capacity (for all the affections of the tangible insofar as it is tangible | 424 b 25 | are perceptible to us by touch)'.
• Whenever a perceptual capacity is lacking, a corresponding organ must also be lacking: 'if indeed when we lack any perceptual capacity we must also lack some perceptual organ;'. This links the possible number of senses to the possible number of organs.
• All things we perceive by direct contact are already covered by touch, and all things we perceive without contact are perceived through simple-body media like air and water: 'all the things that we perceive by touching them ourselves are perceptible by touch, which is a perceptual capacity we in fact have, whereas all those we perceive through media without touching the things themselves we perceive by means of the simple bodies (I mean, for example, air and water); | 424 b 30 |'. This exhausts the modes of access to sensibles.
• If two generically distinct perceptible kinds (e.g. sound and color) share one and the same simple-body medium (e.g. air), then an organ made of that body must be able to perceive both; conversely, if one kind of perceptible has more than one medium (e.g. color through air and water as 'transparent'), then an organ made of either medium will perceive that perceptible: 'if it is the case that [4a] two perceptible objects that are distinct in genus (genos) from each other are perceived though one [simple body], then a being possessed of a perceptual organ of this sort must be capable of perceiving both (for example, if the perceptual organ is composed of air, and air is the medium for both sound and color), whereas [4b] if there is more than one medium for the same perceptible object (for example, air and water for color, since both are transparent), | 425 a 1 | then even a being possessed of [a perceptual organ composed of] only one of them will perceive whatever is perceptible through both;'.
• In fact, the actual sense-organs we observe are composed only of air and water (with fire as common heat and earth as primarily for touch), so there is no remaining elemental composition from which a radically new kind of sense-organ could be made: '[6] if perceptual organs are composed of two of these simple bodies only, namely, air and water (for the eye-jelly is composed of water, the organ of hearing of air, and the organ of smell of one or the other of these), whereas fire either belongs to none or | 425 a 5 | is common to all (for nothing is capable of perceiving without heat), and earth either belongs to none or is most of all a constituent especially connected to touch; then it would follow that there is no perceptual organ outside those composed of water and air,'.
• Some animals already possess all organs built from these media (air and water), so they already possess all corresponding perceptual capacities; there is therefore no sixth capacity waiting on an undiscovered organ: 'and these some animals possess even as things stand, with the result that all the perceptual capacities are possessed by those animals that are not either incomplete or disabled (for it is evident that even | 425 a 10 | the mole has eyes under its skin);'.
• Thus, unless there exists some further simple body or some affection of bodies altogether unknown among terrestrial elements, there is no room left for an additional sense: 'so [7] if there is not some other [simple] body or some affection possessed by none of the bodies that exist here, then no perceptual capacity will be left out. 288'.

Source Quotes

III 1 That there is no perceptual capacity beyond the five (I mean | 424 b 22 | by these sight, hearing, smell, taste, and touch), anyone may be convinced on the basis of the following considerations. For [1] if even as things stand we have perception of everything for which touch is the perceptual capacity (for all the affections of the tangible insofar as it is tangible | 424 b 25 | are perceptible to us by touch); and [2] if indeed when we lack any perceptual capacity we must also lack some perceptual organ; and [3] if all the things that we perceive by touching them ourselves are perceptible by touch, which is a perceptual capacity we in fact have, whereas all those we perceive through media without touching the things themselves we perceive by means of the simple bodies (I mean, for example, air and water); | 424 b 30 | and if it is the case that [4a] two perceptible objects that are distinct in genus (genos) from each other are perceived though one [simple body], then a being possessed of a perceptual organ of this sort must be capable of perceiving both (for example, if the perceptual organ is composed of air, and air is the medium for both sound and color), whereas [4b] if there is more than one medium for the same perceptible object (for example, air and water for color, since both are transparent), | 425 a 1 | then even a being possessed of [a perceptual organ composed of] only one of them will perceive whatever is perceptible through both; and [6] if perceptual organs are composed of two of these simple bodies only, namely, air and water (for the eye-jelly is composed of water, the organ of hearing of air, and the organ of smell of one or the other of these), whereas fire either belongs to none or | 425 a 5 | is common to all (for nothing is capable of perceiving without heat), and earth either belongs to none or is most of all a constituent especially connected to touch; then it would follow that there is no perceptual organ outside those composed of water and air, and these some animals possess even as things stand, with the result that all the perceptual capacities are possessed by those animals that are not either incomplete or disabled (for it is evident that even | 425 a 10 | the mole has eyes under its skin); so [7] if there is not some other [simple] body or some affection possessed by none of the bodies that exist here, then no perceptual capacity will be left out.

III 1 That there is no perceptual capacity beyond the five (I mean | 424 b 22 | by these sight, hearing, smell, taste, and touch), anyone may be convinced on the basis of the following considerations. For [1] if even as things stand we have perception of everything for which touch is the perceptual capacity (for all the affections of the tangible insofar as it is tangible | 424 b 25 | are perceptible to us by touch); and [2] if indeed when we lack any perceptual capacity we must also lack some perceptual organ; and [3] if all the things that we perceive by touching them ourselves are perceptible by touch, which is a perceptual capacity we in fact have, whereas all those we perceive through media without touching the things themselves we perceive by means of the simple bodies (I mean, for example, air and water); | 424 b 30 | and if it is the case that [4a] two perceptible objects that are distinct in genus (genos) from each other are perceived though one [simple body], then a being possessed of a perceptual organ of this sort must be capable of perceiving both (for example, if the perceptual organ is composed of air, and air is the medium for both sound and color), whereas [4b] if there is more than one medium for the same perceptible object (for example, air and water for color, since both are transparent), | 425 a 1 | then even a being possessed of [a perceptual organ composed of] only one of them will perceive whatever is perceptible through both; and [6] if perceptual organs are composed of two of these simple bodies only, namely, air and water (for the eye-jelly is composed of water, the organ of hearing of air, and the organ of smell of one or the other of these), whereas fire either belongs to none or | 425 a 5 | is common to all (for nothing is capable of perceiving without heat), and earth either belongs to none or is most of all a constituent especially connected to touch; then it would follow that there is no perceptual organ outside those composed of water and air, and these some animals possess even as things stand, with the result that all the perceptual capacities are possessed by those animals that are not either incomplete or disabled (for it is evident that even | 425 a 10 | the mole has eyes under its skin); so [7] if there is not some other [simple] body or some affection possessed by none of the bodies that exist here, then no perceptual capacity will be left out. 288 But neither, however, can there be some special perceptual organ for the common perceptibles, which [, then,] we perceive coincidentally by means of each perceptual capacity—for example, | 425 a 15 | movement, rest, {46} shape, magnitude, number, and oneness.

III 1 That there is no perceptual capacity beyond the five (I mean | 424 b 22 | by these sight, hearing, smell, taste, and touch), anyone may be convinced on the basis of the following considerations. For [1] if even as things stand we have perception of everything for which touch is the perceptual capacity (for all the affections of the tangible insofar as it is tangible | 424 b 25 | are perceptible to us by touch); and [2] if indeed when we lack any perceptual capacity we must also lack some perceptual organ; and [3] if all the things that we perceive by touching them ourselves are perceptible by touch, which is a perceptual capacity we in fact have, whereas all those we perceive through media without touching the things themselves we perceive by means of the simple bodies (I mean, for example, air and water); | 424 b 30 | and if it is the case that [4a] two perceptible objects that are distinct in genus (genos) from each other are perceived though one [simple body], then a being possessed of a perceptual organ of this sort must be capable of perceiving both (for example, if the perceptual organ is composed of air, and air is the medium for both sound and color), whereas [4b] if there is more than one medium for the same perceptible object (for example, air and water for color, since both are transparent), | 425 a 1 | then even a being possessed of [a perceptual organ composed of] only one of them will perceive whatever is perceptible through both; and [6] if perceptual organs are composed of two of these simple bodies only, namely, air and water (for the eye-jelly is composed of water, the organ of hearing of air, and the organ of smell of one or the other of these), whereas fire either belongs to none or | 425 a 5 | is common to all (for nothing is capable of perceiving without heat), and earth either belongs to none or is most of all a constituent especially connected to touch; then it would follow that there is no perceptual organ outside those composed of water and air, and these some animals possess even as things stand, with the result that all the perceptual capacities are possessed by those animals that are not either incomplete or disabled (for it is evident that even | 425 a 10 | the mole has eyes under its skin); so [7] if there is not some other [simple] body or some affection possessed by none of the bodies that exist here, then no perceptual capacity will be left out. 288 But neither, however, can there be some special perceptual organ for the common perceptibles, which [, then,] we perceive coincidentally by means of each perceptual capacity—for example, | 425 a 15 | movement, rest, {46} shape, magnitude, number, and oneness. 289 For we perceive all these by movement (for example, magnitude by movement, and so also shape, for shape is a sort of magnitude, rest by non-movement, number by negation of continuity) and by the special objects (for each perceptual capacity perceives one).

Key Concepts

• That there is no perceptual capacity beyond the five (I mean | 424 b 22 | by these sight, hearing, smell, taste, and touch), anyone may be convinced on the basis of the following considerations.
• for all the affections of the tangible insofar as it is tangible | 424 b 25 | are perceptible to us by touch
• all the things that we perceive by touching them ourselves are perceptible by touch, which is a perceptual capacity we in fact have, whereas all those we perceive through media without touching the things themselves we perceive by means of the simple bodies (I mean, for example, air and water); | 424 b 30 |
• if it is the case that [4a] two perceptible objects that are distinct in genus (genos) from each other are perceived though one [simple body], then a being possessed of a perceptual organ of this sort must be capable of perceiving both (for example, if the perceptual organ is composed of air, and air is the medium for both sound and color), whereas [4b] if there is more than one medium for the same perceptible object (for example, air and water for color, since both are transparent), | 425 a 1 | then even a being possessed of [a perceptual organ composed of] only one of them will perceive whatever is perceptible through both;
• if perceptual organs are composed of two of these simple bodies only, namely, air and water (for the eye-jelly is composed of water, the organ of hearing of air, and the organ of smell of one or the other of these), whereas fire either belongs to none or | 425 a 5 | is common to all (for nothing is capable of perceiving without heat), and earth either belongs to none or is most of all a constituent especially connected to touch;
• so [7] if there is not some other [simple] body or some affection possessed by none of the bodies that exist here, then no perceptual capacity will be left out. 288

Context

Beginning of III.1 (424b22–425a12), where Aristotle argues systematically, from the nature of tactile perception, media, elemental composition of organs, and existing animals, that there cannot be more than the five traditional senses.