For Aristotle, the first question in metaphysics is “What is Being?” or in existential parlance, ‘Being-in-itself.’ Being in this sense is different from specific beings, rather it is the totality of existing things, which he calls substances, as well as an adjective applicable to them. Substances make up one element of Being and continue independent of human perception. In contrast, characteristics of things are ‘non-existent’ universals such as ‘dog’ (or “dogness’) as opposed to the existence or being of a particular dog.

In this doctrine then species and genera are secondary and depend on examples of substance. Substances, unlike universals, can exist alone, and are prior to definition and prior to knowledge. Four features applied to ‘substance’ include (1) essence, (2) universals, (3) substrate, and (4) genus. The essence of a thing is its final cause or what a thing is by its very nature and what gives it identity, and thus can be identified with substance. Substrate means matter which is not in itself a particular thing, because separability and ‘this-ness’ are lacking while form is realized in the essence of a concrete thing. Aristotle has a technical term, entelechy, for the actuality, as opposed to potentiality, of a substance.

For Aristotle, material reality, involves three ingredients: (1) substrate (persistent through change), (2) form, and (3) privation (absence of form). Not-being is privation while continual being informs substrate. Form allows substrate to become things.5


Aristotle proposes there is a separate but unchanging being or transcendental supersensible being of which God is the outstanding case.6 As unmoved mover, God turns potentiality into actuality and is the cause of the universe, but not the creator per se, as the universe is eternal. God must be eternal (or timeless) for change to be eternal – a logical necessity since time is simply the measurement of change. The prime mover must also be immaterial so as not to be changeable, since all material things change, that is, God is pure actuality, without matter and not extended in space. God moves objects by desire and thought and is supremely good and divine. Divine thought is about itself as object “in virtue of its participation in what is thought.”7 Likewise there is divinity in the human mind. Our active reason – the ‘Nous’ – is separate from matter, and is transcendental, eternal, even immortal and perhaps even identical with the prime mover, “like God himself thinking in us.”8

(final continuation next post)


4 Don’t look for the word ‘metaphysics’ in Aristotle; it is a later term used to designate the texts after the physics. Aristotle referred to metaphysics as ‘first philosophy.’

5Ibid., page 159-160.

6Ibid., page 160.

7Ibid., page 161.

8Ibid., page 159.

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