Philosophy of Nature: I. Logical Notions
B: Forms, Being, and Knowledge
As we saw in our brief summary of the early history of Greek philosophy in the last chapter, Plato affirmed (along with Pythagoras and Parmenides) the reality of knowledge accessible by reason in contradistinction to the chaos and flux disclosed by the senses (which Heraclitus emphasized). Plato claimed that this stable, ordered knowledge was made possible by the existence of what he called “Forms” (eide (plural of eidos)) or “Ideas” as the fundamental objects of knowledge, especially as exemplified in mathematical knowledge of the sort that Pythagoras emphasized. Plato also supposed that there were eide (Forms or Ideas) of natural physical kinds like trees, human beings, or horses, since we can attain some universal knowledge of these sensible particulars as well.
After Plato’s death, when Aristotle left the Academy and Athens to pursue observational studies of nature, he built on his former teacher’s insights by focusing on the fact that while sensible particular things, especially living things (plants and animals) undergo seemingly constant changes (as indeed Heraclitus had made the centerpiece of his philosophy), there is also a sense in which they enjoy relative permanence. Aristotle rejected Plato’s extreme realism of separate, immaterial Ideas or Forms as a response to Heraclitus, since as separate from material particular things – this dog, that fish, this plant – the Forms did not help explain these particular things, nor give insight into what we don’t already know about them. For Plato, particular sensible material objects merely remind us of the universal Forms or Ideas, and initiate abstract speculation about their separate reality, leading ideally to the contemplation of the Form of the Good-Itself, something akin to (or identical with) God.
Yet, Aristotle also recognized that each of these sensible particular things remain one thing, indeed the same thing over time – that they are relatively stable and possess their own identity. Likewise, he recognized that they have relatively stability across generations – like begetting like. Aristotle thus came to realize that the principle of a thing’s knowability and identity also explains why things of the same sort are of the same sort. That is, things of a given type (species) have something in common, but this does not exist apart from them in an immaterial realm of Ideas, but is intrinsic to the particular things themselves. Indeed, there is a principle in sensible particulars for why instances of red are red, circular shaped things are circular, and why dogs are dogs (and not cats), and so on. Thus, he became committed to the notion that the principle of stability and identity, and thereby the principle by which they are knowable, is something intrinsic and inherent in things themselves.
Knowledge was not of ideas in some separate world, but of the intelligibility or actuality of things in this world. Through the mind’s ability to abstract that intelligibility, we can have unchanging knowledge of the natures of changeable material things.[1]
As we saw in our consideration of logic and the problem of universals, Aristotle followed Plato in calling the principle of actuality, being, and intelligibility “form,” but rather than supposing that these must exist in reality in exactly the same manner as in our minds (as immaterial, abstract, and universal), Aristotle discovered that forms exist in particular material things themselves, and we know them either directly by sense or with our minds by abstracting them from matter. Aristotle thus built upon what was true in Plato’s insights and realized there must be some principles of stability and knowledge which the mind abstracts and identifies, i.e., specifies, in forming real definitions of natural classes of things. He takes over and adapts Plato’s terminology, continuing to use Plato’s term for his Forms or Ideas (eide) as this principle of knowledge (Aristotle’s ‘form,’ however, is usually written in lowercase). Like the word ‘idea’ itself, eide derives from the Greek verb ‘to see’ (idein), and through the Latin of the Middle-Ages, Porphyry’s use of eidos to describe the classes of natural kinds, as we noted before, was translated as ‘species’ from the Latin verb ‘speculare,’ also meaning ‘to see;’ thus, it, too, came into English. All these various words (idea, eide, species) convey the core or root meaning of the ‘look’ or ‘appearance’ of things by which we class them together: if it looks like a duck, etc., that’s (probably) what it is. This formal principle also came to be referred to as a thing’s ‘whatness,’ and hence quiddity (from quid, meaning “what” in Latin)) came into English as the object of definitions, i.e., what definitions identify. Aristotle thus adopts the term ‘form’ as the principle of things’ being, identity, and stability inherent in each thing (not in a separate realm as Plato held). He also focuses on the fact that what we know are “what is” (ti estin in Greek), and so other of his terms for the principle of stability and knowledge are related to the verb “to be” (einai) and “being” (ous, ontos, on) which, again through the Latin equivalents – esse (to be), ens (being) – come into English as “essence.” The term ‘substance,’ indeed, is derived from the Latin sub (under) and stare (to stand) meaning what “stands under (accidents);” “substance” is the standard translation for Aristotle’s ousia, which literally means “being-ness” (as also does “essence”). We will use these terms extensively in explicating Aristotle’s and Aquinas’s analysis of change and the structure, principles and causes of sensible things.
[1] Michael J. Dodds, OP, The Philosophy of Nature, (Oakland: Western Dominican Province 2010), p. 13.
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