In last week’s essay, we thought about the way that one and the same song can be performed in different ways on many different occasions. I advanced the paradoxical claim that the song itself, the thing that is one in all its many performances, is not something we hear with our ears but rather something we grasp with our minds. This week, we will add some nuance to this claim and introduce some technical vocabulary from the Platonic tradition.

Let us return to the idea that a song can be written down in the form of sheet music, read by a skilled musician, and recognized without any sounds being made at all. The song itself, then, is a kind of structure or pattern that we can understand or think about even without hearing it played. Conversely, listening to a particular playing of the song necessarily involves the vibration of the air over a particular span of time in a particular place. Even if I play exactly the same performance of the song over again by hitting the repeat button on my stereo, the second play-through will be distinct from the first and involve different volumes of air being moved through my ear canal at a different time.

This points to a basic distinction that is critical for the whole Platonic tradition, the distinction between what is “intelligible,” i.e. what can be grasped by the mind, and what is “sensible,” i.e. what can be grasped by the senses. In Greek, we can use adjectives as nouns (grammarians call this the “substantive” usage), so “an intelligible” is simply one of these structures or patterns that we have been talking about, while “a sensible” is simply something you can see, hear, taste, touch, or feel.

If you are curious to learn some Greek vocabulary, the terms here are very important for the Platonic tradition. The word for “sense” or “sensation” is αἴσθησις (aisthesis), from which we get the word “aesthetic.” The adjective we derive from the same root is αἰσθητός (aisthetos) meaning “sensible.” If we want to refer to “a sensible thing” we put that adjective in the neuter singular: αἰσθητόν (aistheton). If we want to refer to the whole category of sensible things, we say “the sensibles,” putting the adjective in the neuter plural and adding the definite article: τὰ αἰσθητά (ta aistheta).

We have very similar terms for the “intelligible” side of this distinction. The relevant root word for “mind” or “intelligence,” about which we will have much more to say, is νοῦς (nous). From this we derive the adjective νοητός (noetos), meaning “intelligible.” The same grammatical logic applies to this adjective so “an intelligible” would be a νοητόν (noeton) and “the intelligibles” would be τὰ νοητά (ta noeta). For easy reference, here are the terms in chart form:

Attentive readers will realize that this distinction between sensible things and intelligible things is related to the distinction between material things and immaterial things that comes to feature prominently in later philosophy. It is important to realize, however, that these two distinctions are not exactly the same and they emphasize different features of things. There are many material realities that are not sensible (such as neutrinos), and there may well be immaterial realities that are not intelligible (such as ghosts). When we distinguish between sensible and intelligible, we are not asking whether or not things are made of physical stuff but rather asking what mode of consciousness they require.

So far the distinction seems simple enough. Sensible things are things I see; intelligible things are things I understand. Unfortunately, human consciousness is not so simple. In reality, we never simply see or hear anything at all. Instead, because we are intelligent beings, our seeing and hearing is always shot through with understanding. Return again to the example of hearing a song. We can distinguish between the pure sensations coming through my ears and the intelligible pattern I recognize with my mind. In concrete experience, however, it is impossible to just hear the pure sensations. We always hear the sounds as patterns that our minds recognize. When I hear Bill Evans play those opening chords, I do not hear vibrations in the air. I hear chords, and more specifically, I hear the opening chords of a specific song that I recognize. Even when the sounds are entirely new to us or very strange, our minds are already at work categorizing and understanding.

Vision and the other senses work similarly. It is a common idea in philosophy that the basic data of vision are colors. But this is a mistake. I do not first see patches of green and gray, think about it for a second, and then figure out that I am looking at a tree. Instead, I simply see a tree. In fact, the order is reversed: In the first moment of vision I see a tree, and then with a little effort and shift of attention, such as that which a painter might make, I can see patches of green and gray. Some art instructors even recommend squinting or blurring your vision a little so that you can trick your mind into not seeing the tree and instead see the colors. Even with such tricks, however, it is impossible to avoid seeing that the colors are the same colors as those you have seen before and that they are arranged in a particular pattern. Again, I want to emphasize that this pattern recognition is not a second moment deduced from a first moment of pure sensation. The human mind functions in such a way that all this visual processing and pattern recognition occurs before sensations ever arrive at the level of consciousness.

It is common to think that sensations are the basic stuff of our lives and intelligibles are strange philosophical abstractions. The exact opposite, however, is true. Since we never actually experience pure sensations, the basic fabric of our day-to-day experience, all our memories, and all our ordinary thinking are made up of intelligibles. If anything, pure sensations are abstractions. They are the unintelligible residue that we are left with when we philosophically cut away the intelligible patterns within sensory experience. We are left with the idea of pure sensations that we recognize must be an important ingredient in sensory experience. The idea of pure sensations, then, is an abstraction we make when we reflect on the structure of experience but not something we ever experience directly.

Unlike pure sensations, sensibles are not abstractions. They are the objects that we experience through sensory experience—trees, rocks, faces, bird songs, and breath—which we have already observed is inevitably saturated with intelligibility. In one sense, these sensibles are the basic objects of our ordinary experience, then, but in the following essays we will see that it is precisely the intelligible aspect of sensibles that we experience, think about, remember, and discuss. Between the two, then, sensibles in their sensuousness are the strange ones; intelligibles, by contrast, are all you’ve ever known.