Substance and Accident

Natural Philosophy – Substance and Accident

What the meaning of “IS” is

First, as a kind of preliminary and as tool for philosophical discourse, one should be familiar with the basic distinctions of Aristotle’s logic. The basic logical distinction for our purposes is between accident (what exists in but is not said of another) and substance (what does not exist in another & not said of another). What is said of another, i.e., predicated of something, is the universal class to which it belongs.

As an example of what Aristotle means, consider what is named by the word “white.” The reality that this word names (a particular color) is not said of a dog, Fido, for instance, in the way that “color” is said of “white.” That is, “this dog is white” does not predicate the color white of the dog, but signifies that the white color exists in the dog, or that the dog has a white color. But when color is said of white, as in “white is a color,” what is meant is that white belongs to the class of colors. Color is the genus, of which white is a species. And the white of this dog, Fido, is a particular instance of the species of white color, just as Fido himself is a particular instance of the species, the universal class, of dogs.

Furthermore, the particular white color is understood to exist in “this dog, Fido;” one does not find any “white” except that is in “this dog” or some other thing. This way of speaking can be contrasted with another, as for example “This thing is Socrates.” “Socrates” does not name the same kind of reality that “white” does in the previous example. “Socrates” is not said of “this thing” in the same way as “white” is, and “Socrates” does not exist IN “this thing.” Rather, “Socrates” IS “this thing,” and the sentence “this thing is Socrates” is understood to assert an identity between the two realities named.

This basic notion of Aristotle’s logic reflects the basic distinction in the way reality is structured and reflects the basic way that we view reality. The fundamental distinction is between substance and accident. Substance is whatever is a natural kind of thing and exists in its own right. Examples are rocks, trees, animals, etc. What an animal is, a dog for example, is basically the same whether it is black or brown, here or there, etc. A dog is a substance since it exists in its own right; it does not exist in something else, the way a color does.

The other distinction is between what is said of and not said of another: universals are said of, or predicated of, other things, while particulars are not said of anything else. Among what are said of another, i.e., universals, they may either be a species, which is said of many particular individuals, or a genus, which is said of many species, or of many genera below it.

Substance and Accidents

Accidents are the modifications that substance undergo, but that do not change the kind of thing that each substance is. Accidents only exist when they are the accidents of some substance. Examples are colors, weight, motion. For Aristotle there are 10 categories into which things naturally fall. They are

  • Substance, and
  • Nine Accidents:
    • Quantity,
    • Quality,
    • Relation,
    • Action,
    • Passion,
    • Time,
    • Place,
    • Disposition (the arrangement of parts), and
    • Rainment (whether a thing is dressed or armed, etc.)

All these distinctions are basically logical, but in a sense they reflect the structure of reality. Indeed, Aristotle tells us, that the primary sense of substance is the particular individual, and the universal, genus or species, is substance in a secondary sense. This is because both accidents (white or color in general) and species and genera, only ever exist because the individual particular exists. One never finds any substance that we experience without some accidents, nor an accident that is not the accident of a substance. Every dog, for instance, has some color, place, size. Nevertheless, it is obvious that what a dog is is not the same as its color, or its size, etc. And without particular dogs (Fido, Rover, etc.) there would be no species of dog. In this way, Aristotle clearly opposes the extreme Realism of Plato, though he is still a Realist (as opposed to a Nominalist or Conceptualist) because he thinks that dogs are dogs because they share in the species, or essential nature, of dogs.

Please support the Thomistic Philosophy Page with a gift of any amount.

%d bloggers like this: