Some objections to the virtual presence of elements.

Most versions of hylomorphism* say that any form added to the substantial is accidental. Thus if elements as substantial then things like horses, men, and cows are accidental. Modus ponens seems to give us material reductionism, and so non-reductive hylomorphists opt for modus tollens, and say that elements are only virtually present in the things made out of them. On this account, electrons are only virtually present in carbon, carbon only virtually present in an organic molecule, the molecule only virtually present in the living cell, the cell only virtually present in the organ, etc. The story seems to be something of a stretch when we hit the higher levels: can’t we just look at cells? How is this virtual presence somehow non-actual? Call that objection one.

Objection two is this: if the structure of an element enters into an explanation of a compound, then it cannot be virtually present in it, since “structure” seems to be taken on the side of form, and form on the side of act. Now while there is no problem with explaining density or mass by the virtual presence of molecules, since these things do not require any formal structure on the side of the element, if you ask a chemist what properties of things he explains by the formal structure of their elements then he’ll likely say “everything”. Spectroscopy depends in the structure of the atom, as does x-ray crystallography, the explanation of valences, the change of phases, the reason why some elements are reactive and others not, the explanation of the generation of electricity, etc.  It even explains why (to point to the common argument for virtual presence) why hydrogen and oxygen burn but water does not.

We bracket the Scotist doctrine of the plurality of substantial forms for the moment.



  1. thenyssan said,

    October 20, 2014 at 2:18 pm

    Very interested to hear you say more about virtual presence. I don’t recall you doing much with this before, and I’ve always struggled to get much beyond the level you’ve sketched out here.

    • October 20, 2014 at 4:41 pm

      As far as I can tell, X is virtually present in Y whenever Y can make X. So cookies are virtually present in one sense in a shelf of ingredients and in another way in the Chef. In a slightly different sense, fire is virtually present in fire, matches, and lightning.

      There’s one additional part to the definition: virtual presence is not an actual presence in the world. One gets atoms out of a compound not like one might get bricks out of a wall but like fire out of a match.

      I’ve personally known venerable thomists who deny that there are actual atomic structures in natural things. Feser defends the virtual presence of atoms in a compound on pp. 177-184 in his latest book, and he’s well within the long tradition of the manuals in doing so. He leans heavily on Oderberg’s Real Essentialism, and one should follow out those citations too. My objections in this post don’t come up, but they seem to me to be the fundamental ones. Why aren’t cells virtually present too? Why does atomic structure explain so much about compounds?

      • socraticum said,

        October 20, 2014 at 9:09 pm

        I’m inclined to think cells are virtually present in their wholes as well.

      • socraticum said,

        October 20, 2014 at 9:10 pm

        (That is, if there is anything to a cell as such beyond it’s parthood)

      • Stan Grove said,

        October 21, 2014 at 4:52 am

        Greetings James (it’s been a while…)!

        Your present subject seems to be crucial, e.g. in making sense of quantum physics / chemistry. “Virtual,” it may be worth recalling, is to be taken in the root sense: (some of) the power(s) of a lower substance (not the substance as such) become present in the higher substance (this per Aquinas), even as the substantial “structure” of the lower substance becomes part of the “structure” of the higher — but not without some modification. Thus oxygen includes among its powers or capacities that of entering into combination with hydrogen to form water; some of its powers, in this sense, are realized and manifested in water. But oxygen as such is not in water — otherwise it would act, even in water, like oxygen (supporting combustion rather than [often] hindering it, combining with hydrogen to form water, etc.).

        To the evidence of the senses (i.e. that drawn from the properties of higher substances as compared with those of the lower from which they are composed) we can also add that provided by quantum chemistry: atoms and subatomic particles are definable as dynamic distributions of electrical charge in space, but it is precisely these distributions that change somewhat when lower constituents become caught up in higher substances. Thus, the electron distribution (in fact, the very size and shape of the atoms) characteristic of free oxygen is not identical to the distribution (size, shape) characteristic of the “oxygen component” of water. A spatial reconfiguration here is the sign of a formal change. (Recall also that matter sub quantitate determinata is the spatializing and individuating principle.) So while it is not quite correct to say that atoms are “not actually present” in the substances which they compose, it is OK to say that their actual presence is modified from that which they possessed when on their own.

        We can be misled by the senses when applying this principle to macroscopic things — sure, cells as seemingly discrete units are right there before our eyes. But note that [a] cells of multicellular organisms do what they do (and are therefore cognizable as cells) only as parts in the whole; [b] if there are any cases where cells that live naturally by themselves can also enter into multicellular organisms (are there really any such? Volvox? I dunno), I dare say they will exhibit somewhat different sets of properties and behaviors in the unicellular and multicellular states, analogous to the case of elemental and water-forming oxygen already mentioned; [c] should any cells that live within multicellular organisms be extracted and made to live on their own, surely we could say that they are now a different organism. A culture of living human skin cells in a petri dish is not a human.

      • October 21, 2014 at 12:49 pm

        Hi Stan, It’s been a long time indeed. Good to hear from you.

        My idea of a response was going to focus on imperfect substances of the sort STA describes in QDDA a. 1. sc. some things are hoc aliquid without having a complete species. This is part of a larger tripartite ontology of substance, accident, and parts of substance, where “parts” are any term of analysis.

        That said, I’m not convinced that Thomists have taken atomic theory as something illuminating and deserving to be incorporated into our understanding of nature as opposed to being a set of suspicious claims that we should distinguish our way out of and then promptly forget about. Thomists tend to forget how they once insisted on Universal causes, natural places, the first mobile, the impossibility of infinite rectilinear motion, the generative power of the sun, the contact between local movers, absolute rest, the plenum, the perfection of circular motion, the ontological separation of space and time, etc. All these are lost, though some more than others, and we have yet to put together a philosophical account of nature from out of the ruins.

        But to the point at hand. Take the “water does’t burn” account of virtual presence:

        Contributing to combustion is an essential property of the substance oxygen
        Water in combination does not contribute to combustion. etc.

        Thomists take this as establishing a conclusion, but many chemists, as far as I understand them, seem to want to take it as a reductio against the major premise. The chemists have a point: contributing to combustion does not seem essential property of oxygen, any more than “burning when it is put on the surface of the sun” is an essential property of ants. All such unfortunate ants will burn, to be sure, and even burn necessarily, and even burn necessarily because of principles that reduce to the essence of ants, but this is still extrinsic to what is essential to them. Similar things might be said about boiling points (which more describe a sort of interaction a substance has with its environment, and so are more between substances than of one of them). The essential properties of oxygen are more like the sort of thing one would put on the periodic table: mass, number, orbital, number of valence electrons, subatomic structure and composition, etc. These sorts of things seem to count as what is essential to the element – with what is lost by composition or phase change seen as ipso facto non-essential. There is, as in all things, some variation in what can count as essential, but the chemist seems to learn more by assuming that what is sloughed off in composition was not essential than by assuming that some change in essence occurred. True, the chemist does posit a chemical change as opposed to a physical change, but the distinction is hazy and seems like something we wave at in chapter one of the textbook before forgetting about it.

        You’re right that we have to give some account of cells in a body that makes them different sorts of thing than a cloud of protozoa, but I’m not sure if the best account of this is in terms of a virtual presence. The Scotist option of a multiplicity of substantial forms might seem more probable given the completeness of the cells in question. There’s no getting around the axiom that no part as such is complete, but the cell does have a bona fide self-activity and even an autonomy even when it composes a tissue, and so I’d want to balance your objections to cellular substantiality against the findings that show the cell as a self as opposed to a part: it metabolizes, reproduces, feeds, dies, responds to stimuli, etc. All these seem to require a recognizable even if minimal self, even when the cell is essentially a part.

  2. vishmehr24 said,

    October 22, 2014 at 6:09 am

    how is this virtual presence expressed precisely?
    Do we say that oxygen is virtually present in water or that oxygen atom is virtually present in water molecule?

    In my opinion, it seems more natural to say that oxygen is virtually present in water. And in the language we try to consistently maintain a distinction between substances and individual atoms or molecules.

    thus oxygen is not the same as an oxygen molecule or atom. This should resolve the problem you mention– whereas the oxygen atom is actually present in a water molecule, the oxygen element is only virtually present in water substance.

    • October 22, 2014 at 9:36 am

      Stan Grove’s account is very good, but my suspicion is that he would disagree – there’s a proximate and remote presence in things.

      “Virtual presence” on my account is a sort of imperfect substance, sc. one for which the perfect substance is the element in its uncompounded state. Cells of the multicellular organism on this account aren’t virtually present since they have no separate perfect existence but are essentially parts.

      Even on this account, a mere positing of some powers of the element in the compound does not seem robust enough to get us the results we get in chemistry. Take solid-state spectroscopy of some compound. Are we to say that the elements of the compound preserve only their power to tell us that they have their identifiable structure, without having that structure? And if they have that structure, how are they not substantially present? Saying this seems ad hoc. But the processes here are complex and I certainly don’t understand all the assumptions, algorithms and reconstructions of data that are involved.

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