"The form of a thing, we are told, is its essence and primary substance. Forms are substantial, although universals are not. When a man makes a brazen sphere, both the matter and the form already existed, and all that he does is to bring them together; the man does not make the form, any more than he makes the brass. Not everything has matter; there are eternal things, and these have no matter, except those of them that are movable in space. Things increase in actuality by acquiring form; matter without form is only a potentiality. The view that forms are substances, which exist independently of the matter in which they are exemplified, seems to expose Aristotle to his own arguments against Platonic ideas. A form is intended by him to be something quite different from a universal, but it has many of the same characteristics. Form is, we are told, more real than matter; this is reminiscent of the sole reality of the ideas. The change that Aristotle makes in Plato’s metaphysic is, it would seem, less than he represents it as being. This view is taken by Zeller, who, on the question of matter and form, says:

"The final explanation of Aristotle’s want of clearness on this subject is, however, to be found in the fact that he had only half emancipated himself, as we shall see, from Plato’s tendency to hypostatise ideas. The ‘Forms’ had for him, as the ‘Ideas’ had for Plato, a metaphysical existence of their own, as conditioning all individual things. And keenly as he followed the growth of ideas out of experience, it is none the less true that these ideas, especially at the point where they are farthest removed from experience and immediate perception, are metamorphosed in the end from a logical product of human thought into an immediate presentment of a supersensible world, and the object, in that sense, of an intellectual intuition."

I do not see how Aristotle could have found a reply to this criticism. The only answer that I can imagine would be one that maintained that no two things could have the same form. If a man makes two brass spheres (we should have to say), each has its own special sphericity, which is substantial and particular, an instance of the universal “sphericity,” but not identical with it. I do not think the language of the passages I quoted would readily support this interpretation. And it would be open to the objection that the particular sphericity would, on Aristotle’s view, be unknowable, whereas it is of the essence of his metaphysics that, as there comes to be more of form and less of matter, things become gradually more knowable."

I don't care how it is in Aristotle really. I just question Russell's interpretation.

So he says that if there are a particular special form for every particular thing, then particular form would be unknowable.

Why? Okay, there would be a lot of forms in this case. Too many of them, okay. But they still can become known, can't they? To understand them would be long, but still possible.

  • This is related (or equivalent) to the question of haecceities. I don't know what Russell thought, if anything specifically, about the concept of haecceities, but you might look into Russell's type theory for details about what kind of universal/particular (here, a type/term or type/token) distinction Russell made, and then why he might have objected to there being types individuated per any and every term. Commented Aug 17, 2023 at 17:03
  • Because knowledge is based on abstraction, i.e. grouping together, according to some point of view, many objects/facts. Commented Aug 19, 2023 at 8:33

1 Answer 1


What Russell is saying is not that in Aristotle's system, the form is unknowable, but that it must be unknowable. This is because it contrasts with Plato's framework, which turns the object into an "immediate presentment of a supersensible world" and transforms it into an "immediate presentment of an intellectual intuition." However, as Russell mentioned, and you are well aware of, "it is of the essence of his metaphysics that, as there comes to be more of form and less of matter, things become gradually more knowable." It seems that you are currently confusing Russell's intended meanings of "must" and "is" assertions.

  • No, I wasn't asking clearly, I guess. I intended to ask: Why Russell said that Aristotle would say in this situation that particular forms would be unknowable? Why did he put this words in Aristotle's mouth? Because I see no reason for particular forms to become unknowable in this situation (situation where there is a special particular form for every particular thing) Commented Aug 17, 2023 at 17:44

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .