Wednesday, July 20, 2016

Aristotle's and Aquinas' ideas about Substance and Form.

Something about Aristotelean-Thomist (A-T) metaphysics bothers me, and Jon Garvey reminds me of it again in a recent post.
He says above “substance” has to do (in A-T thought) with form.

To me, this is an abuse of language and of all metaphysical intuition!
Normally, we say thing is 'substance in a form', or a thing is made out of some substance and is arranged in some form. So 'substance' and 'form' are combined (metaphysically) to make a particular thing. A substance can be arranged in many possible forms, and a given form may be made out of many possible substances. But, if we specify substance and form, then we specify a thing.

But, as Jon points out, this natural way of speaking is completely up-ended in A-T language. There 'substance' and 'form' are practically identified! They are of course completely allowed to define words how they like. But, if I were starting a new metaphysics suitable for science, that is NOT how I would proceed. It is completely bizarre!

In fact, Aristotle bears some responsibility for this. He talks of things made of matter, and then 'form' as 'everything else that makes a thing what it is'. But that leave unclear how causal powers of thing are supposed to exist: since they are not matter they must be form. This conflates (in a stupid way) the ideas of 'form' as structure and 'form as causal power'.

Then Aquinas bears further responsibility. He sees the above problem. He wants to attribute causal powers to substance (a good idea, I say). But, rather than fixing Aristotle's definition of 'form', he then conflates (in a stupid way) the ideas of 'form' and 'substance'. He has no option left. But that results in the idea of a 'substantial form'. That might be ok, except (as I point out just above), any clean new metaphysics would distinguish 'substance' and 'form'. A-T is not clean in that respect.

Essence is that which makes something what it is.
Substance is that out of which something is made.

The format of Thomistic metaphysics then takes a somewhat dyadic structure of descending generality: (i) essence and existence, (ii) substance and accident, (iii) matter and form. (much good Thomist presentation!)

In general, we can (must!) diverge from materialism. We can be guided by Aquinas’ insights, not to mention more general Christian insights. But that does not mean necessarily following the A-T system in all its glorious details. Instead, see my previous post for what a new kind of metaphysics could be that talks properly about substance and form.

Tuesday, July 19, 2016

Physical and Mental Substances: what are the stuffs of nature?

Here is a potted summary of a non-reductive 'propensity account' of physical and mental substances:

Quantum theory must deal with substance, but just not substance of the classical material or atomistic kind.  Rather, something that perseveres through time without existing in a actualized form at every moment. The substance would be something like the 'potentiality' or 'propensity' for acting, and that acting occurs with non-zero time steps, not continuously. This is the 'propensity interpretation' of quantum mechanics, initiated by Heisenberg and Popper. Because of the finite time steps, propensities exist and persist from one event to another actualization. Between events, therefore, they are the substances of quantum things.

We talk about mental information, and ask "what property of substance, makes it amenable to human cognition". You (like many others) are asking, 'what is the stuff of mind?'. My answer is an extrapolation of what I said above for quantum physics. It is 'potentiality' or 'propensity' but now of mental kinds. What is that, you ask? Do I know it? Yes: I say. It is the 'love' or 'desire' that make a person. For loves and desires are what in us persons that does persist. Again we make actualizing decisions intermittently. Between those decisions it is our love which persist. Love is our mental/personal substance. Just (certainly not!) material substance!

Quantum objects are propensity-substances in various forms. Those forms are the wave functions of quantum theory.
Mental objects are love-substances in various forms. Those forms are the information of mental kind, a.k.a thoughts and perceptions. The actions of love (a.k.a. decisions) have physical effects.

These ideas are based on the ideas of the kind Aristotle might have had without much effort, though in fact he did not. Just remember that there are two kinds of substances (at least), and the kinds are not reduced to another, or aggregates of other kinds. It is the job of physicists and psychologists to determine how the two kinds of substances actually cause things, and hence what they actually do.

There are functional correspondences between the way physical and mental things exist and operate, even though the substances involved are completely different and can never be transformed one into another.