Matter

Lots of people know of Aristotle's and Aquinas's theories that matter is the substratum of change, that it is 'pure potentiality', that it cannot exist without form, and so forth. Henry of Ghent, Scotus, and Ockham have a very different view of matter.

Roughly speaking, matter is the basic stuff that all material substances are ultimately composed of. For instance, although animals are composed of organic tissue, tissue is composed of cells, and so forth, at rock bottom there’s a fundamental kind of stuff that all material substances are ultimately made from. This basic stuff is called ‘matter’, and the earth is filled with it.

Matter is not, as we might imagine today, just another name for atoms or quarks or whatever other sort of particle we think is the fundamental building block of material bodies. Matter cannot be broken down into fundamental ‘particles’ or indivisible parts. It’s more like an amorphous kind of stuff that can always be divided into smaller and smaller parts, similar to the way that a line can always be divided into shorter segments.

But matter is ‘amorphous’ in the sense that it does not have any form itself — it is not, that is, itself a composite of matter and form. Rather, matter is a purely receptive sort of material that can be made into different kinds of material substances.

This is not to say that matter is a ‘bare substrate’, as it were, that has no features of its own. On the contrary, matter is real stuff; it has parts (as I’ve already indicated), and it exists in space. Ockham even thinks matter is extended in three dimensions. (Scotus denies that matter is extended, but he still thinks it exists in particular places, perhaps similar to the way that electrons have no dimensions but still exist here or there.)

Further matter has specific features. It is the foundation for relations, and it has the capacity to take on substantial forms. More precisely, there is a discrete power that exists in matter to receive each different kind of substantial form. So there is a power p1 to receive the form of fire, a power p2 to receive the form of water, and so forth for every substantial form that matter can receive. (Matter has no powers to receive accidental forms.)

Nor is matter just ‘pure potentiality’ — i.e., a mere abstraction of the potential in material substances to be transformed into different substances. Henry, Scotus, and Ockham all believe that God could create a lump of matter without any forms, so matter is at least the sort of thing that in principle can exist all by itself.

Aquinas denies all this, I think. He explicitly says that matter cannot exist without form, and even God cannot create matter all by itself, without a form. Matter does not have any features of its own except that it is a 'pure potentiality'. (I don't know if Aquinas thinks matter has parts or exists in places. I wouldn't think so, but I don't know.)

Still, it’s difficult to imagine what a lump of matter is like, even on the views of Henry, Scotus, and Ockham. As I’ve already hinted, the best we can do is imagine an amorphous blob. But even that’s not quite right, and there’s a reason for this. Medieval Aristotelians believe that we can only know things through their forms, so we cannot imagine something that doesn’t have some particular form.

But just because we can’t imagine it does not mean that it’s not there. As our authors see it, matter must exist because we see material substances coming to be and passing away all the time, and given the hypothesis that change requires a recipient, there must be something there that gains and loses the forms that constitute those material substances.

(Besides, say Henry, Scotus, and Ockham, God isn't limited to knowledge by forms, and he has a proper 'idea' of matter -- and that means that matter has a nature; i.e., it has essential properties that define just like every other kind of entity.)

Per se unity 2

Here are some more thoughts on 'per se unity'. I had a post on this earlier.

For Aristotle, change occurs when a subject x acquires a form F. There are, however, two broad types of change: substantial change, and accidental change.

In substantial change, the subject is a lump of matter, and the form is a substantial form. The matter and substantial form together constitute a substance (e.g., Socrates' matter and a substantial form constitute the human person Socrates).

In accidental change, on the other hand, the subject is a substance, and the form is an accidental form (e.g., when Socrates goes to the beach and gets a tan, Socrates is the subject, and his tan color is an accidental form).

According to Aristotle, matter and a substantial form have 'substantial unity' (or 'per se unity', as it's also called), and a substance and its accident has 'accidental unity'. And for Aristotle, the constituents in a substantial unity are tied together much more tightly than those in an accidental unity. For instance, the matter and form in Socrates are tied together more tightly than Socrates and his tan color.

But as far as I can see, it's very difficult to identify the precise way that a substantial unity is tighter than an accidental unity. In both cases, the constituents are related to each other in many of the same ways. Consider the following.

(1) In both cases, the subject can survive the gain and loss of the form. For instance, Socrates can lose his tan, but Socrates' matter can likewise lose his human form.

(2) In both cases, the form can only exist by inhering in a subject. An accident like a tan color can only exist when it inheres in a subject (like Socrates), but Aristotle thinks that applies to substantial forms too: Socrates' human form can only exist when it inheres in a lump of matter.

(The Christian scholastics believe human forms can survive the death of their bodies, but that's a special case. We can easily use a different example to make the same point: even the Christian scholastics believe that Beulah the cow's substantial form can only exist in a lump of matter.)

(3) In both cases, the identity of the composite depends on the identity of its constituents. For Aristotle, Socrates would be destroyed if his matter and form were separated, but 'tan-Socrates' also cannot survive if its constituents are separated: 'tan-Socrates' ceases to exist when Socrates loses his tan.

(4) In both cases, the subject and the form are related in terms of potentiality and actuality. For instance, Socrates' matter has the potential to have a human form, and Socrates' human form actualizes that potential. Likewise, Socrates has the potential to be tan, and his tan color actualizes that potential too.

So for both accidental and substantial unities, the form actualizes a potential in the subject, the form can only exist by inhering in the subject, the subject can survive the loss of the form, and the subject and the form together constitute a unity that cannot survive if the subject and the form are taken apart. In what way, then, are substantial unities 'tighter' than accidental unities? I don't know.

It's tempting to say that while Socrates' tan color is tied to Socrates only 'accidentally' (i.e., 'loosely'), a human substantial form is tied to Socrates essentially (i.e., much more 'tightly'). But this does not help, for it equivocates on the meaning of 'Socrates'.

When we say the tan color is accidental to Socrates, we are taking Socrates as the subject of the tan color. But when we say a human substantial form is essential to Socrates, we are taking Socrates as the composite of a subject (matter) and a form.

Thus, although Socrates is the subject of his tan color, Socrates is not the subject of his substantial form. Rather, Socrates' matter is the subject of his substantial form. So while it's true that Socrates' tan color is accidental to its subject (Socrates), it's also true that Socrates' human form is accidental to its subject (Socrates' matter).

Similarly, although Socrates is the composite of which his substantial form is an essential component, Socrates is not the composite of which his tan color is an essential component. Rather, 'tan-Socrates' is the composite of which the tan color is an essential component. So while it's true that Socrates' human form is an essential component of the composite Socrates, it's also true that Socrate's tan color is an essential component of the composite 'tan-Socrates'.

Thus, we need to be careful when we talk about how constituents are 'essential' or 'accidental' to their subjects and/or composites. In both cases, the forms are accidental to their subjects, but essential to their composites.

Avicenna on necessity and possibility

Avicenna famously says that God is 'necessary in himself', while all creatures are both 'possible in themselves' and 'necessary from another'.

There are two distinctions here.

1. The first distinction is between something that is 'necessary in itself' and something that is 'possible in itself'. God is 'necessary in himself', while everything else is 'possible in itself'.

It would be a mistake to interpret this as a distinction between necessary and contingent beings, as if that which is 'necessary in itself' exists in every possible world, while that which is 'possible in itself' exists in some but not all worlds.

This would be wrong not only because Avicenna doesn't believe in possible worlds (for Avicenna, there are no possible worlds -- just the one, necessary world), but also because Avicenna thinks everything that is 'possible in itself' is produced necessarily. Since anything that's produced necessarily would exist in every possible world, it would be incoherent to also say that it would exist in some but not all worlds.

(Averroes thinks Avicenna is suggesting just that, so he accuses Avicenna of incoherence. But Averroes' interpretation is incorrect.)

So we should not think that to be 'possible in itself' means to be 'contingent'. Rather, we should take it to mean just what Avicenna says: that which is 'necessary in itself' exists without being produced, while that which is 'possible in itself' exists because it is produced.

And that, I think, is the bottom line. That's all that Avicenna means when he talks about being 'necessary in itself' and 'possible in itself'. There's nothing there about modality.

Now, Avicenna says some other things about being 'necessary' or 'possible in itself', but I don't think they take away from my point. They are as follows.

(a) Something is 'necessary in itself' if its non-existence entails a contradiction. In other words, something that is 'necessary in itself' is the sort of thing that simply must exist. Consequently, it exists on its own, so it need not, and in fact it cannot, be produced. (It just exists on its own, and you can't produce what already exists.)

(b) By contrast, if something is produced, then it cannot be 'necessary in itself'. If it were 'necessary in itself', then it would exist on its own, so it could not be produced. But since it is produced, it must not be 'necessary in itself'.

(c) Further, since it's produced, it must not be 'impossible in itself', for impossible things cannot exist at all.

(d) Its existence, then, must be within the bounds of possibility. So it is 'possible in itself'.

But as I said, I don't see how any of that takes away from the basic point: for Avicenna, to be 'necessary in itself' means to exist without being produced, and to be 'possible in itself' means to exist because its produced. And that's all it means.

Some people talk as if Avicenna thinks there is a realm of 'possibles' standing in front of God, and God chooses what to actualize.

But I don't think that's right either. Avicenna uses the word 'possible' only because that which is produced is neither 'necessary' nor 'impossible' in itself, and the only word left is 'possible'. But unfortunately, the word 'possible' suggests contingency, a realm of 'possibles', etc.

I think a better label would be 'not necessary in itself'. Avicenna's real point is just that a product is produced; it's not the sort of thing that just exists without being produced. As Aquinas nicely puts it in Sent. 1.8.3.2: 'That which acquires its existence from another does not exist necessarily in itself, as Avicenna proves'.

So to say that something is 'necessary in itself' means nothing more than that it exists without being produced, and to say that something is 'possible in itself' means nothing more than that it exists because it is produced. That's it. No modality here.

2. The second distinction, however, does have to do with modality. This is a distinction between something that is produced necessarily and something that is produced contingently (or, in Avicenna's terminology, between what is 'necessary from another' and what is 'possible from another').

For those who believe in possible worlds, we could put the point like this: a product is 'necessary from another' if it's produced in every possible world, but it is 'possible from another' if it's produced in some but not all worlds.

Note that just because something is produced does not entail whether it is produced necessarily or contingently. To put it in terms of possible worlds again, a product might be produced in every world, or it might be produced only in some.

This is why I say that the distinction between being 'necessary' or 'possible in itself' is not a distinction between necessary and contingent beings. It is just a distinction between being produced or unproduced. The distinction between being necessary or contingent comes up here, i.e., in the distinction between being 'necessary' or 'possible from another'.

For reasons I don't want to go into here, I should note that Avicenna's distinction between being 'necessary' or 'possible from another' is only a logical distinction. Avicenna believes that every product is produced necessarily, so there is nothing that is genuinely contingent in Avicenna's universe. So the distinction is just logical.

Nevertheless, the point still stands: to be produced is one thing, and to be produced necessarily or contingently is another. Again, to put it in terms of possible worlds, a product cannot exist in a world all by itself: if it exists in a world, it must exist with its producer. But that says nothing about how many worlds a product exists in. It might exist in none (if it was never produced), it might exist in some if it's produced contingently), or it might exist in all (if it's produced necessarily).

Obviously, the distinction between being 'necessary' and 'possible from another' only applies to products. It cannot apply to something that is 'necessary in itself', for such things are not produced, so there's no option to be produced 'necessarily' or 'contingently'. Only products can be produced 'necessarily' or 'contingently'.

Consequently, anything that exists without being produced has only the one feature: that of being 'necessary in itself', while anything that is produced has two features: that of being 'possible in itself', and that of being 'necessary' or 'possible from another'.