Lecture 5 — The nature of color

Concerning sensible objects, in relation to each sensitive part—I mean, for instance, color and sound and odor and taste and touch—it was said in a general way in the discussions On the Soul what their action is; and what it is to operate in relation to each sensitive part. But it is necessary to say what each of them is; that is, it must be considered what color is, what sound is, what odor is, what flavor is, and similarly also concerning touch. And first concerning color.

Each, then, is spoken of in two ways: on one hand in actuality, on the other in potentiality. Accordingly, what color in actuality is, and sound, how they are the same as or other than the sense powers in actuality, namely seeing and hearing, has been said in the discussions On the Soul. But let us now say what each of them is that it should cause sensing and actuality.

Accordingly, as was said about light in those discussions, it is the color of the transparent accidentally. For when something lit up exists in the transparent, the presence is light, and the privation darkness.

But what we call the transparent is not a property of air or water or any of the bodies mentioned, but is a common nature and power. It is not separate, but it is present in these and in other bodies, in some to a greater extent, in some to a lesser.

Therefore, as there is necessarily a limit of bodies, so there also is of this. Now the nature of light is in the unlimited transparent. But it is obvious that there will be a limit of the transparent that is in bodies, and that this is color is clear from what happens: for color is on the limit or is the limit. Hence the Pythagoreans called color an “epiphany”; for it is on the limit of a body, but it is not the limit of the body.

Now one must think that it is the same nature that is colored from without and intrinsically. Air and water appear as colored things, for the dawn is such a thing. But in this case, because it is in something indeterminate, neither the air nor the sea has the same color to those who approach close up and from afar. But in bodies, unless something containing makes a change, there is a determinate fantasia of color. Therefore it is clear that both in the former and in the latter it is the same thing that is receptive of color.

Therefore the transparent, according as it exists in bodies—and it exists in all of them, to a greater or lesser extent—is what causes colors to be participated in. But because color is on the limit, it will be a limit of this.

Therefore color will be the limit of the transparent in a determinate body.

And in transparent things such as water and any other such thing, and in whatever seems to have a color of its own—in all these it is likewise at the limit.

77. Concerning sensible objects (439a6). After the Philosopher has applied the consideration about sense powers of animals to sense-organs, here he applies it to sensible objects themselves.

First, he states his intention.

Second, he carries out his proposal, where he says accordingly, as was said about light (439a18; [80]).

On the first point, he does two things.

First, he proposes his intention.

Second, he clarifies what he said, where he says each, then, is spoken of in two ways (439a12; [79]).

Accordingly, he first speaks of proper sensible objects, those perceived in relation to each sensitive part, that is, each individual sense-organ, which he says to distinguish them from common sensibles. The proper sensibles are color, sound, and odor, which are sensed through sight, hearing, and smell; and taste and touch—that is, the objects of these senses. He says that it was said in On the Soul in a general way both how these act on a sense power and the nature of the sense power’s operation in relation to each organ affected by the above-mentioned sensible objects. (Aristotle, On the Soul 2.6–11; cf. Aquinas, Commentary on Aristotle’s On the Soul, bk. 2, lect. 13–23, nn. 383–550.) For it was said in On the Soul 2 that a sense power is a sensible object in potentiality, and that sensible objects make a sense power be in actuality. (Aristotle, On the Soul 2.5, 416b32–418a6; cf. Aquinas, Commentary on Aristotle’s On the Soul, bk. 2, lect. 10, nn. 352–54.) But now it must be considered what each sensible object is in itself, that is, what color is, what sound is, what odor is, what flavor is, and similarly concerning touch—that is, the objects of touch. But first color, which is the object of sight, must be discussed, because sight is the most spiritual of the senses.

78. It is not to be understood by this that he intends to make a determination about all these sensible objects in this book, but rather that consideration of them all is necessary to the proposed intention. But objects of touch are either properties of elements, namely hot, cold, moisture, and dryness, about which a determination was made in the book On Generation and Corruption; (Aristotle, On Generation and Corruption 2.2–3, 329b6–331a6; cf. Aquinas, Commentary on Aristotle’s On Generation and Corruption, bk. 2, lect. 2–3.) or they are properties of individual bodies, such as hardness and softness, and so on, about which a determination was made in the book, The Meteorology. (Aristotle, Meteorology 4.4–8, 382a8–384b23.) So what is left now is to make a determination about three things, namely color, odor, and flavor. For a determination about sound was made in the book On the Soul, (Cf. Aquinas, Commentary on Aristotle’s On the Soul, bk. 2, lect. 16–18, nn. 439–78.) because the account of the production of sound is the same as the account of the alteration of the auditory organ by sound, and the way in which sense-organs are altered by sensible objects belongs to the consideration made in the book On the Soul. (Aristotle, On the Soul 2.8, 419b4–421a6; cf. Aquinas, Commentary on Aristotle’s On the Soul, bk. 2, lect. 10–13, nn. 350–98.)

79. Then, when he says each, then, is spoken of in two ways (439a12), he explains what was said, namely that it must be considered what color is, what flavor is, etc.

For each of these exists in two ways: in one way inasmuch as it is sensed in actuality, and in another way inasmuch as it is sensible in potentiality. What each of them is according to actuality—that is, according as color, flavor, or any other sensible object, is in actuality perceived by sense—has been said in On the Soul. (Aristotle, On the Soul 2.7–12; cf. Aquinas, Commentary on Aristotle’s On the Soul, bk. 2, lect. 14–24, nn. 399–863.) That is, it was said how each of them is the same as or other than a sense power in actuality, such as seeing or hearing: for the visible in actuality is the same as seeing in actuality, but the visible in potentiality is not the same as sight in potentiality. Accordingly, what each of the sensible objects is in actuality was said in On the Soul, where a determination was made about the sense powers in actuality. (Aristotle, On the Soul 3.2, 425b26–426a1.) But what each thing that is of such a nature as to cause the sense power to be in actuality is in itself must be said now, in the present book.

80. Then, when he says accordingly, as was said about light (439a18), he makes a determination about sensible objects in the order already established:

first color;

second flavor, where he says odor and flavor must be discussed (440b28; [118]);

and third odor, where he says odors must be understood in the same way (442b27; [162]).

The first part is divided into two parts.

In the first, he shows what color in general is.

In the second, he makes a determination about differences among colors, where he says accordingly, what causes light (439b14; [95]).

On the first point, he does two things.

First, he presents the principles of color.

Second, he investigates the definition of color on the basis of these principles, where he says therefore, as there is necessarily a limit of bodies (439a25; [87]).

Now there are two principles of color: one is formal, namely light; the other is material, namely the transparent.

Accordingly, he first touches on the formal principle, light;

and second on the material principle, the transparent, where he says but what we call the transparent (439a21; [82]).

Accordingly, he first says that, as was said in the book On the Soul, light is the color of the transparent. (Aristotle, On the Soul 2.7; cf. Aquinas, Commentary on Aristotle’s On the Soul, bk. 2, lect. 14, n. 405.) He says this according to an analogy (proportio): as color is the form and actuality of a colored body, so light is the form and actuality of the transparent.

81. But they are different inasmuch as a colored body has the cause of its color in itself, but a transparent body has its light only from something else. This is why he says that light is the color of the transparent accidentally, that is, through something else, and not that light is the actuality of the transparent as such. He shows that light is the actuality of the transparent through something else in the following way. When a body that is lit up—that is, bright in actuality—is present to the transparent, light is caused in the transparent by the presence of that body, and darkness by its privation. But it is not so with color, because the color remains in a colored body whatever is present to or absent from it, although it may not be in actuality visible without light.

82. Then, when he says but what we call the transparent (439a21), he makes a determination about the transparent.

He says that what is called the transparent is not a property of either air or water or any such body—for instance glass and other transparent bodies—but is a common “nature” found in many bodies—that is, a natural property found in many things—one that he also calls a “power” (virtus) inasmuch as it is a principle of vision. Now Plato held that, just as what is common is separate in intelligibility (ratio), so it is also separate in existence (esse). Therefore, in order to eliminate this position, he adds that the nature of the transparent is not a separate nature, but is in these sensible bodies—namely air and water—and also others, in some to a greater extent, and in some to a lesser.

83. To make this clear, it must be known that, as the Philosopher says in On the Soul 2, the visible is not color alone, but also something else, which is apprehended by reason but unnamed. (Aristotle, On the Soul 2.7, 418a26–28; cf. Aquinas, Commentary on Aristotle’s On the Soul, bk. 2, lect. 14, n. 399; lect. 15, 429–30.) Accordingly, in the genus of the visible, taken in general, there is something that stands as actuality and something that stands as potentiality. What is in this genus as actuality is not a proper quality of any of the elements, but rather light itself, which exists first in the heavenly body, from which it is derived to lower bodies. What is in this genus as potentiality is what is properly receptive of light, which is arranged in an order of three levels.

84. The first level is reached when what is receptive of light is totally filled with it, being, as it were, perfectly brought to actuality, so that it cannot receive any further quality or form of this kind. Of all bodies this is most true of the sun, which is why the body of the sun cannot be a medium in sight that receives and transmits a visible form. And the property of shining, descending in a certain order, reaches fire, and then, beyond that, certain bodies that, because of the smallness of their light, can shine only at night, as was said above. (1.2, 437a31–32; cf. ch. 2, n. 40.)

85. The second level belongs to what does not of itself have light in actuality, but is receptive of light through the whole of itself. Such bodies are properly called “perspicuous” or “transparent,” or also “diaphanous,” for “phenomenon” in Greek means the same as “visible.” This property of being transparent is found to the greatest degree in heavenly bodies, except for the bodies of the stars, which conceal what is behind them. Second, it is in fire, that is, fire in its proper sphere, because of its fineness. Third, it is in air, fourth in water, and fifth even in certain bodies made of earth, because of an abundance of air or water that is also in them.

86. The third and lowest level belongs to earth, which is farthest away from the heavenly body, and is by nature receptive of light to the least degree, namely, only on its surface. For its external parts, because of their thickness, overshadow the internal ones so that light cannot reach the latter.

Now although it is only in the case of bodies of the intermediate level that one properly speaks of the “transparent” or “diaphanous” according to the proper meaning of the term, nevertheless, generally speaking, that can be called “transparent” which is receptive of light in any way whatsoever, and it is in this sense that the Philosopher seems to be speaking here of “the transparent.” (Gauthier, p. 35, points out that this discussion of the levels of the transparent is adapted from Alexander, but is clearer. See Alexander of Aphrodisias, On Aristotle’s “On Sense-Perception,” trans. Towey, pp. 50–53.)

87. Then, when he says therefore, as there is necessarily a limit of bodies (439a25), he investigates the definition of color.

First, he investigates its genus.

Second, he investigates its difference, where he says now one must think that it is the same nature (439a33; [90]).

Third, he concludes to the definition, where he says therefore color will be (439b11; [93]).

Now it must be considered that one should always put the subject in the definition of an accident, as is said in Metaphysics 7, (Aristotle, Metaphysics 7.5, 1030b14–1031a14; cf. Aquinas, Commentary on Metaphysics, bk. 7, lect. 4, 1342–55; cf. Aquinas, On Being and Essence, ch. 6; ST I-II.53.2, ad 3.) although this is done in different ways.

For if an accident is defined in the abstract, the subject is put in place of the difference and what pertains to the essence of the accident is put in place of the genus, as when it is said that “snubness is curvedness of nose.”

But when an accident is defined in the concrete, conversely the subject is put in place of the genus, as when it is said that “a snub is a nose that is curved.”

Accordingly, because here color is to be defined in the abstract, Aristotle first begins by investigating, in place of a genus, what color itself essentially is.

He concludes from what was said that, since the transparent is not a separate nature, but one existing in bodies, it is necessary that, just as there is a limit of bodies in which this nature is found if the bodies are finite, so also there must be a limit of the transparent itself, which signifies a quality of such bodies.

88. And the argument is the same for all qualities of bodies that are accidentally quantities as a result of the quantities of the bodies, and hence are accidentally limited as a result of the limits of the bodies.

Accordingly, it must be considered that, just as some bodies (for instance, those that consist of earth) are said to be “limited” because they are limited by limits of their own, and others are said to be “unlimited” because they are limited not by limits of their own, but by the limits of other things, so it is in the case of the transparent. One kind is “unlimited” of itself because it has in itself nothing determinate by which it may be seen, but another is “limited” because it does have something in itself by which it may be seen with respect to its own limit.

89. Accordingly, the unlimited transparent is receptive of light, the nature of which is such as to be received not only at a limit, but throughout a whole. But it is clear that there is a limit of this transparent that, as was said, is a quality existing in bodies. And that this is color is clear from what happens. For colored bodies are seen only at their limits, from which it is evident that color either is the limit of a body or is on the limit of a body. And hence it is that the Pythagoreans called color an “epiphany”—that is, an “appearance on”—because what appears on the surface of bodies is color. But it is not true that color is the limit of a body, as the Pythagoreans held, because thus it would be a surface or line or point. But it is on the limit of a body, just as the nature of the transparent is on bodies.

90. Then, when he says now one must think that it is the same nature (439a33), he investigates what is put in the definition of color as the difference, namely its subject, which is the transparent.

He says that one must think that it is the same nature that is receptive of color in bodies that are colored from without—that is, not by their own color but by something outside them—and in those that are colored intrinsically by their own color. Those that are colored from without are transparent, for instance air and water; he makes this clear with the color that appears at dawn through the shining of the sun’s rays on certain bodies.

91. However, he does provide a difference between bodies that are colored from without and those colored of themselves. In those that are colored from without, because they do not have of themselves a determinate color, the color does not seem to be the same from close up and from afar, as is clear in the case of the air and the water of the sea, which from afar appear to be of another color than they do from close up; for because their color is seen by a reflection, its appearance necessarily varies with variation of the location of those looking at it because of the different angles of reflection. But in bodies that of themselves have a determinate color, there is a determinate “fantasia”—that is, appearance—of color, and it does not vary with the different locations of those looking at it, except perhaps accidentally, for instance when a containing body causes a change of appearance; or when one color is seen through another, as when what is contained in a vessel of red glass seems red; or again by the kind of reflection of light such as appears in the pigeon’s neck.

92. Therefore, because color, which is seen in both kinds of body, does not differ with respect to the proper subject of color, but only with respect to the cause of its appearance, which is either intrinsic or extrinsic, it is clear that in both cases it is the same thing that is receptive of color. And because the transparent is what is receptive of color in what is colored from without, the transparent is clearly also what causes intrinsically colored things to participate in color. Indeed, the transparent is found in bodies according to more and less, as was said: bodies that have more air or water have more of the transparent, and those that have an overabundance of earth have less.

Therefore if we unite the two things said—that color is on the limit of a body, and that bodies participate in color with respect to the transparent—it follows that color is the limit of the transparent.

93. Then, when he says therefore color will be (439b11), he concludes to the definition of color.

He does so first in the case of what is colored of itself, intrinsically.

Second, in the case of what is colored from without, where he says and in transparent things (439b12).

Accordingly, he concludes that color is the limit of the transparent. He adds in a determinate body, because such bodies are those that are of themselves colored, and what is per se should be put in the definition of a thing.

Now his saying that color is the limit of the transparent is not opposed to what he said above, that color is not a limit. For he said that with reference to the limit of a body, but here he is speaking of the limit of the transparent, which he calls a quality of a body, like hot and white. Thus color is not in the category of quantity—like surface, which is the limit of a body—but in the category of quality. The transparent is also in the category of quality, because a limit and that of which it is the limit belong to one category. And just as bodies have surface in their interior in potentiality but not actuality, so they are also colored in their interior in potentiality but not actuality, and this potentiality is brought to actuality when division of the body occurs. For what is interior does not in actuality have the power to move sight, a power that belongs per se to color.

94. Then, when he says and in transparent things, he clarifies the nature (ratio) of color in the case of unlimited transparent things such as water, or any other thing of this kind that has a color: in all these there is color only with respect to the limit.