Course Notes – Thomas Hofweber, “A Puzzle About Ontology”

By Daniel A. Kaufman

Over the years, our degree program has always required something along the lines of a technical, Analytic philosophy course.  At one time it was Philosophy of Mind, at another, Philosophy of Science, while at yet another time, it was the philosophies of Mind and Language, as well as Metaphysics, all bundled together.  Back in 1999, I was hired, in part, to teach the Philosophy of Mind course, but eventually migrated to other areas connected to Aesthetics and the Philosophy of Art, the teaching of which was the primary reason for my employment.  In the meantime, another faculty member took over the course and transformed it into “Mind, Language, and Reality.”  He retired, recently, and I had the (dis)pleasure of teaching this course, which I found unwieldy and overloaded with material, in the sort of way that you wind up teaching a lot of things not very well.  I refused to teach the course in this form, the result of which was the creation of yet another course to fill this slot in the curriculum, “Knowledge and Reality: Contemporary Approaches,” an upper-division offering in (mostly) 20th century Epistemology and Metaphysics.  Yes, stuff written over a hundred years ago counts as “contemporary” in philosophy, and if you really want a good laugh, when philosophers use the word ‘modern’, they mean work written in the sixteenth and seventeenth centuries.

The course is one of the more challenging ones I’ve had to teach, in good part because most, if not all of the material presupposes substantial knowledge of both the history of philosophy – and especially, of the Modern period – and logic, including modal logic.  While we have a great Department and offer what I think is a very respectable degree program, we are limited by our small size – just seven faculty – and by the backgrounds of our students, which are for the most part, quite modest, both educationally and financially.  We offer just one basic logic course, one history of Ancient philosophy survey, and one history of Modern philosophy survey.  Our students really aren’t prepared, then, to read and discuss Wittgenstein, Quine, Davidson, Goodman, and many of the other Analytic heavy hitters who appear in the course, and this means that I have to find a way to make this very difficult material digestible, which means that I have to know it inside and out, forwards and backwards, myself.  Class prep, needless to say, is labor intensive.

We finished the Epistemology unit last week, and students have just turned in their exams, which cover everything from G.E. Moore’s “Proof of an External World,” Wittgenstein’s “On Certainty,” Gettier’s “Is Justified True Belief, Knowledge?” Crispin Wright’s “Facts and Certainty,” and others.  Now we are onto Metaphysics, where our first topic is Ontology and our first article was Quine’s “On What There Is,” which went down relatively well.  Now we are in the middle of Thomas Hofweber’s paper, “A Puzzle About Ontology,” in which a number of the points made in Quine’s landmark paper are called into question and, as I put it to the class, “problematized.” (1)  One thing in particular about Hofweber’s struck me as particularly interesting and is what I am going to sketch out here, in this inaugural edition of “Course Notes.”


According to Quine, ontological commitment is a matter of theory selection and quantification. (2)  We determine which are our best scientific theories of the world, look to what they quantify over, and these are the things that we take to exist.

Quine rejects wholeheartedly the idea that ontological commitment can be “read off” of ordinary subject-predicate sentences; that from “The table is red,” one can conclude that redness exists or from “Four is an even number” that numbers exist.  This is because surface-grammar notwithstanding, one can interpret these sentences in ways, such that neither the subject nor the predicate refer to an actual entity.  Only explicitly quantificational sentences straightforwardly entail ontological commitments, according to Quine, and which quantificational sentences we should accept depends upon whether or not our best scientific theories must include them.

Hofweber directly confronts this dimension of Quine’s thesis, and it is in his confrontation that the point of interest I want to share with you arises.

Hofweber observes, first, that it certainly looks as if ontological commitments can be read off of ordinary subject-predicate sentences and second, that is not at all clear that explicitly quantificational statements are always indicative of ontological commitments.  He makes these points by way of an analysis of some very interesting ways we use certain kinds of sentences.

Take the following, which Hofweber refers to as “metaphysically innocent,” insofar as it suggests no particular metaphysics:

A.  Fido is a dog.

Now, consider this sentence:

B.  Fido has the property of being a dog.

Hofweber describes this sentence as being “metaphysically loaded,” as it would seem to suggest a metaphysics and specifically, a metaphysics of properties.   A puzzling thing is that this sentence is not only straightforwardly entailed by the first, but is materially equivalent to it.  That is, it has precisely the same truth-conditions: both (A) and (B) are made true and false by the same fact, namely, whether or not Fido is a dog.

The question of how a metaphysically innocent sentence can be so easily and smoothly translated into a metaphysically loaded sentence strikes me as interesting in itself, especially considering their material equivalence.  Certainly, there is disagreement as to whether truth-conditions tell us all there is to know about a sentence’s content, but there are many highly regarded thinkers who say that they do, including Quine, Davidson, and every other proponent of so-called “extensionalist” semantics, and regardless, it’s not at all obvious how two statements that express exactly the same fact can have such radically different implications. (3)

But things get even worse, for from (B), one can deduce:

C.  There is a property that Fido has, namely, that of being a dog.

Which is a straightforward quantification over properties that would seem impossible to interpret away, as we did with (A).  The mystery, now, is compounded, for (C) is straightforwardly entailed by (B) (and via (B), from (A)), and is also materially equivalent to both (A) and (B).  It too is made true or false by whether or not Fido is a dog.  So, from a metaphysically innocent statement, one can deduce an explicitly, unavoidably metaphysical one, with a very specific ontological commitment, one that is materially equivalent to its metaphysically innocent predecessor.   Curioser and Curioser.

What Hofweber wants to know, logic aside, is what people actually use constructions like (B) and (C) for and whether, typically, they intend to signal ontological commitment when they do so, and it is here that his analysis gets really interesting, not so much because of what it shows about ontological commitment, but because of what it reveals about the many and fascinating ways in which we use language.

Let’s look at another set of statements:

(D)  I had two bagels.

(E)  The number of bagels I had is two.

(F)  The person who had two bagels is me.

Like our first group of statements, (D), (E), and (F) are materially equivalent.  Their truth or falsity is a matter of whether or not I ate two bagels.   But notice that while (D) states this fact neutrally, (E) and (F) state it with a different focus.  (E) Stresses how many bagels I had and (F) stresses that it is I who had them.

In speech, this sort of focus is typically effected phonetically, by way of inflection, tone, volume, cadence, etc.  In writing, however, the only way to do it is either through markings whose purpose is to simulate phonetic effects – italics, boldface, underlining and the like – or syntactically, which is what we see here.

Focus has a substantial effect on communication, with the effect of these sentences varying widely, despite their common truth-conditions.  One important effect is to bring a particular element into a position of special prominence.  Consequently, one statement may be appropriate in a given context, while another may be completely inappropriate, even if, as a matter of propositional content, the two statements state exactly the same fact.  If, for example, I asked you:

(G)  Who had two bagels?

(E) would be an inappropriate answer, even though, truth-conditionally, it is identical to (D) and (F), both of which would be appropriate.  This is because of the relevant syntactical focus of (E) on the how many, rather than on the who, which is what (G) is asking about.

Notice something else: That I aim to focus on one element or another has entirely to do with the sort of conversation I am having, and it is not at all clear that in doing so, I am also intending to commit to entities.  I don’t make the focus that I do in (E) in order to ontologically commit to numbers or in (F) to ontologically commit to persons.  I do so in order to stress certain aspects of the fact that I am describing, whether to appropriately answer certain questions – like (D) – perhaps forestall certain questions, make certain things clear that perhaps were unclear, etc., but certainly not because I want to advance a Platonic view of numbers or a Cartesian view of personhood.  Hofweber’s analysis, then, would seem to explain the relationship between metaphysically innocent and metaphysically loaded statements, without lending any support to the suggestion that beyond intended shifts in focus, the latter represent any sort of desire to commit ourselves ontologically.

The problem still nags at us, however, because of the quantificational statements that also seem to follow:

(H) There is a number, which is the number of bagels I had, namely two.

Now, this statement is straightforwardly metaphysical.  It is unambiguously ontological.  And – dammit – it follows, logically, from (D)and is materially equivalent to it (and to (E) and (F)).  From the standpoint of just what is involved in – and what involves us in — ontological commitments, it represents a tremendous problem, insofar as such sentences can be generated out of every ordinary subject predicate sentence, with all the ontologically inflationary implications that follow.  But it is not my focus, here, and thus, is a fitting place to draw this little bit of classroom reportage to a close.


(1)  Thomas Hofweber, “A Puzzle About Ontology,” Nous, Vol. 39, No. 2 (2005).


(3)  See, for example, Donald Davidson, “Truth and Meaning,” Synthese, Vol. 17, No. 3 (1967).






5 responses to “Course Notes – Thomas Hofweber, “A Puzzle About Ontology””

  1. mpboyle56

    Kudos on this new feature! Really enjoyed this analysis of Hofweber. Great stuff!

  2. davidlduffy

    “metaphysically loaded..has the property of”: If I’d said “Fido is an instantiation of the Platonic Dog”, I guess this is also “materially equivalent” to the first, but it makes a bit clearer what other commitments you are assenting to when you agree “True”. This might have something to say about underdetermination of scientific theory too, but “property” seems too philosophical.

  3. Interesting summary of a difficult issue. I’m still digesting the links.

    I will say, in first response, that I came to the conclusion some time ago that any language at all not only makes ‘ontological commitments’ but posits a metaphysics. ‘Such is the way of the world,’ or ‘such is life’ – what do such nonchalant comments mean if not that ‘the world is ordered in such a way that the events we are discussing would inevitably happen (or events very much like them).’ Thus the comments suggest an entire universe in which certain events are destined to happen.

    “I’m going to the store” – Thus I assert that there is a subject; this subject has agency; there is at least one entity that can be called a ‘store’ to which an agent may ‘go,’ which assumes an agency of motility. How could it be otherwise?

    I see here another instance in which the Analytic tradition, by assuming scientific theories the model of language (since expounding ‘certain knowledge’ of a kind), get the process of thinking and its relation to language precisely backward.

    But they aren’t alone in this. Although I much admire Kant, and even have some fondness for the German Idealists, they also were quite mistaken to hold that ‘logic is the science of thought,’ that somehow language begins in the quest for certain truth. That’s clearly not the case, but a hope. Philosophy ought to be a reflection on what is (including language, just as it is). Once this is admitted, then we can read the language people actually use, to discover what they really believe. Determining the truth of these beliefs is another matter.

  4. EJWinner wrote:

    I came to the conclusion some time ago that any language at all not only makes ‘ontological commitments’ but posits a metaphysics. ‘Such is the way of the world,’ or ‘such is life’ – what do such nonchalant comments mean if not that ‘the world is ordered in such a way that the events we are discussing would inevitably happen (or events very much like them).’


    But that was the whole point of Russell’s theory of descriptions, EJ. To show how sentences with fictional names could have truth values, because the names could be interpreted as a cluster of descriptions. Yes, Kripke problematized this much later, but nonetheless, there was a real reason for going the route Russell did. Otherwise, we have truth-value problems for statements like “The Present King of France is Bald.”

  5. An excellent outline.

    Interestingly, it has always been controversial that, fir example, C follows from B and that H follows from D

    You can’t do that in first order logic. It is only fairly recently that second order logic has gained general acceptance.