Monday, 3 May 2010

Open Thread on Metaphysics

We thought it would be a good idea to have a thread devoted to any questions folk have about the metaphysics that we've met in Aquinas.

Fire away in the responses!


  1. My first question is about essences. We talk a lot about what makes something good. Two sessions ago we looked at the following:

    A thing is good inasmuch as its desirable.
    It's desirable iinasmuch as perfect.
    It's perfect inasmuch as actual.

    And being actual is a matter of matching up with the essence, as far as I remember our discussions.

    So, if we have a cat, a four legged cat is better than a three legged cat because it's more actual, it's actualised 'being four-legged' whereas the other cat hasn't.

    Which sounds okay at first, but then you realise that in fact there is no "better" in this case, because if 'being four-legged' is part of the essence of what it is to be a cat, then the second cat isn't actually a cat, and they can't really be compared.

    I must be missing something, just not sure what :)

  2. See?

    It's like I said. People are more interested in shoes than in metaphysics.


  3. Simon,

    I think what might be missing here is the essence of "essence" ;-)

    For any substance (let's stay with concrete particulars for the moment), possessing an essence, it will possess a number of accidents. Some of those accidents will "flow" naturally from its essence (these are called "essential accidents" or "properties") and some will not (these are called "non-essential accidents"). It's a fundamental point of epistemology that we infer essences from properties (and we may be mistaken in our inference!)

    However (and it’s a big “however”, and part of what makes inferring essences from properties difficult), although properties “flow” from essences, a particular substance need not actually possess all its properties. A particular substance may be a “faulty” example of such a substance.

    So, to take the example of a cat: We recognize a number of facts about cats as being non-essential accidents (the colour of a cat, for example) but we also recognize certain facts about cats as flowing from their essences (being four legged animals, for example). When we come across a three-legged cat, we simply recognize it as a (deficient) cat. It certainly isn’t a different sort of animal entirely.

  4. Welcome berenike. It's lovely to see you here!

    You'll have to forgive the occasional slow pace of this blog - it all has to fit round real life!

    Now, considering shoes, is it essential to a shoe that it possess its partner?

  5. Okay, I'm gonna take one step back: What things does Aquinas count as substances?

    As far as I'm aware Aristotle counts both concrete particulars and species (but not genera) as substances? And as such both particulars and species have essences (so there are two kinds of essence). Is that Aquinas' understanding?

    So, regarding particulars: Above you suggest that a particular's essence is not necessarily the set of properties (such as being four legged) a thing has (or "should have") but something underlying those properties, from which they "flow" from. (So contrary to our discussion in the group essences are not blueprints for what a thing should be like.) But is that the definition of the essence of the particular or the species?

    I think I can accept quite well particulars possessing individual-essences, so my essence perhaps is my exact DNA make-up. And I can see how certain natural kinds could possess kind-essences, water having the essence H2O say. The problem I see with the species-essences of living things say, is that, if one accepts evolution, then it seems there are no hard and fast lines here - it is not the case as Aristotle thought that the species have just always existed in the manner we find them today. But if that is the case then what is the essence upon which the set of properties flow which I (hopefully) possess rest?

  6. Hi Simon,

    I’m a bit tied up for a couple of days, so may I offer a quick (and probably inadequate) partial answer to your last posting?

    What does Aquinas count as a substance?

    Informally, he takes substances to be those sorts of things that subsist in themselves. More formally, he suggests that a substance is a thing to whose quiddity it belongs to be not in something else. He is aware, however, that offering a formal definition of substance is hard (and may in principle be impossible) because “substance” is the most general genus and therefore there is no more general genus of which it would be a species (and to “define” something we need to place it as a species in a genus).

    Aristotle, Aquinas and Substances.

    Roughly speaking in the “Categories” Aristotle counts concrete particulars as “primary substances” and species as “secondary substances”. It’s worth noting that he goes on to provide a developed form of his hylomorphism in the “Metaphysics” and scholars have argued down the centuries as to whether the notion of substance given in the Categories is consistent with the notion given in the “Metaphysics”. Aquinas tends to follow the Aristotle of the Metaphysics; so that he uses substance in two basics modes. The first corresponds to the individual subject (suppositum in Latin) and the second corresponds to the intrinsic formal cause of such substances – that is, the substantial form.

    Particulars and Essences

    Let’s distinguish between three theories of essences. The first is the “bundle theory” of essences which states that the essence of a thing is simply given by the collection of its properties. The second is the “bare substratum” theory in which the essence of a substance is given by its properties together with a non-property principle of individuation. Aristotle and Aquinas reject these two theories (basically on the grounds that they provide no explanation of why any particular set of properties goes together). So the third theory that they subscribe to is the hylomorphic one; the substantial form defines what kind of thing a thing is and matter provides the principle of individuation. So, thinking of secondary substance in terms of unindividuated substantial form and of primary substance in terms of individuated substantial form makes some kind of sense (with quite a few simplifications along the way).

    You write:

    “So contrary to our discussion in the group essences are not blueprints for what a thing should be like.)”

    I’ll admit, I cannot remember what was said in the discussion  can you expand please?

    Also, please can you expand a little on the point you make about evolution? (n.b. David Oderberg devotes a whole chapter to biology, evolution and Real Essentialism in his book.)

  7. Simon (K)
    You seem to be looking at three things here
    a) St Thomas’s account of ‘good’, ie the proposition that everything is good in so far as it is actual
    b) St Thomas’s account of what makes the world intelligible.
    c) In particular, the link between the two, which asserts that we know what a thing ‘ought’ to be.
    It seems to me that there are a couple of ways we could go with this:
    (a) Come up with an alternative account of what ‘good’ might mean.
    (b) Stick with an account of ‘good’ as ‘actual’ but abandon the idea of essence/substance (ie that which makes a thing the sort of thing it is) because it is difficult to apply to observable cases (eg 3 legged cats, evolution etc)
    (c) Accept the difficulties of ‘essence’ and go with St Thomas.

    A. Alternative accounts of ‘good’
    Feels like one of us needs to post a short paper summarising the main alternatives, and looking at the consequences for St Thomas’s theology!
    B. Abandoning the idea of Essence
    We could argue that a thing’s essence is unique to that thing. Essence binds together certain phenomena eg all the cells in my body so that I can be pointed at and named, but there is no quiddidity which enables the observer to understand what is common between me and you. There is no property/nature we share, such as ‘rational animal’.
    A consequence of this approach is that we need to find an alternative account of what underpins intelligibility and language, replacing ideas such as genus, species and difference. Again, a short paper might help develop our thinking. We also lose the idea of evil as privation, although understanding alternatives to St Thomas’s idea of ‘good’ might help with this.
    C. Accept the difficulties of ‘essence’
    Call me lazy, but this is my favoured route for now! Why?
    (a) I don’t have an alternative philosophical system to appeal to. Now that is lazy!!
    (b) In spite of difficulties with applying ideas like essence, I think it is a good tool for understanding a complicated world. For example, we could argue about whether a three legged cat is a cat or not. Most people would say it is. They would also say it is a deficient cat (it won’t do what cats should do eg catch mice). I might get my tool box out and start hacking off further legs, shaving the cat etc. We might eventually agree that ‘it’ stopped being a cat and became a corpse. Happy to cremate said corpse if that is what it takes to get agreement on when it stops being a cat. Evolution works the same way. There are domestic cats, big cats, wild cats. We can tweak the genes until suddenly, we stop thinking we have a cat. However, while change creates difficult cases, we use ideas of essence, genus and difference to discuss the grey areas that evolution and dissection create.

    PS. No animals were hurt in the course of this thought experiment.

  8. Thanks Simon and Steve. I do have Real Essentialism on my list to read, unfortunately, it being fairly expensive and not in the library means it keeps getting bumped. I am however reading E J Lowe and Aquinas' On Being and Essence. What I'm finding with the Aquinas is that his notion of essence is radically different to how it tends to be thought of today, at least how I've always thought of it prior to philosophical study.

    I've always considered it as a kind of blue-print, which would be what you describe as the "bundle theory" above Simon; I try to imagine it as a blue-print rather than a bundle to avoid confusion with Hume's bundle theory of substance. This is how essences are treated too by some contemporary essentialist philosophers (Plantinga, for example). And (at least as I understood it) that is how we were talking in our last meeting; it seemed implicit that they were a set of properties and we were talking lots about things becoming more perfect as they fulfilled these properties.

    I'm going to study the Aquinas paper in depth and re-formulate my questions if they still exist, or post new questions if they're answered :)

  9. Simon,

    Another book (that is in the library!) worth taking a look at is Michael Loux's "Metaphysics: A Contemporary Introduction", which is thoroughly modern in its outlook whilst being sympathetic to realism. It's very helpful in situating these older (and better!) metaphysical ideas in the modern milieux.