Thursday, September 20, 2007

A Limitation on Dialetheism

First, I should acknowledge my indebtedness to Greg Littmann and Keith Simmons, whose essay “A Critique of Dialetheism” was the inspiration for this post.[1]

Dialetheism, for those not in the know, is the thesis that that some contradictions are true. It is platitudinous that some of the things people say are true and others false—and some, dialetheists add, are both true and false. At first sight, this is an odd yet intriguing view. But why believe it?

Dialetheism is usually motivated by considerations involving logical and semantic paradoxes, most famously by the Liar paradox. One of the most basic versions of the Liar is (1):

(1) This statement is false.

Is (1) true? If it is, then what it says is the case, and since what (1) says that it’s false, it’s false. But if (1) is false, then what it says is not the case, and since (1) says that it is false, it is false that it is false, and hence (1) is true. So if (1) is true, it’s false, and if it’s false, it’s true. Contradiction.

There are various things one could say at this point, but the important thing is what the dialetheist says, and what the dialetheist says is that (1) is both true and false. There are many things which can be said in favor of this view, some of them very compelling. There are also many things which can be said against it that are equally compelling. My aim, however, is not to argue either that dialetheism must be accepted or rejected as a matter of principle, but rather to show that the dialetheic treatment of logical and semantic paradoxes cannot be extended to all versions of the Liar. Consider for a moment (2):

(2) This statement has the same truth value as “0 = 1”.

Assume (2) is false. If so, it must have a different truth value than “0 = 1”, for what (2) says is that they have the same value. Since “0 = 1” is false, (2), if it has a different value, must be true. But if (2) is true, it has the same truth value as “0 = 1”, for that they have the same truth value is precisely what (2) says. Now if (2) is true, and it has the same truth value as “0 = 1”, then “0 = 1” must also be true, and hence we can conclude that 0 = 1 ![2]

We cannot give (2) a dialetheic treatment—holding that it is both true and false— for we can substitute any falsehood we like for “0 = 1” and use the paradox to show it must be true as well as false. We would then end up with trivialism—the view everything is both true and false! Since (2) cannot be solved by dialetheic means, it must have a different, consistent solution. There are many avenues we could pursue, such as tweaking the T-schema, holding that (2) expresses no proposition, adopting some form of the theory of types, etc. , but the point is that at least one of them must be successful. Granting this, why can’t we solve more traditional variants of the Liar in the same way? Dialetheism might still be true—in some attenuated epistemic sense of “might”—but even so it is not a perfectly general solution to all Liar-like paradoxes. If other kinds of Liar statements can be given the same treatment as (2), whatever that may be, dialetheism loses much of its motivation. If other reasons can be found for believing in true contradictions, well and good—but so long as consistent solutions are on the table, I think they ought to be preferred.

[1] “A Critique of Dialetheism”, in The Law of Non-Contradiction: New Philosophical Essays, Oxford University Press 2006. In particular I was inspired by their sentence (Z):

(Z) has the same complete and correct evaluation as the sentence ‘1+1=3’.

(Z) can be found in footnote 26 on page 333 (Paperback version).

[2]If we had started out by assuming (2) is true, we could have reached the same conclusion in half the time.

Saturday, September 08, 2007

Where I Stand

I got this idea from this post of Alan Rhoda's at Analyzer, who got it from a post of Johnny-Dee's at Fides Quaerens Intellectum, who in turn got it from a post of Andrew Bailey's at Ratiocination. The object is to list your current stances on issues in those areas of philosophy that interest you. If you're a philosophy blogger and you're reading this, consider yourself tagged. :-D

Here's mine:


  • Constitution is not identity: One thing can’t literally be identical to many.

  • Eternalism: The past, present, and future all exist. The “passage of time” is an illusion.

  • Ersatz modal realism: There are no pure possibilia. There are other possible worlds, but they are non-concrete; most likely they are sets of propositions or maximal states of affairs.

  • Anti -Humeanism: There are necessary connections between at least some distinct existences.

  • Platonism: There are universals answering to at least some predicates and/or concepts, though probably not to all. There are also some other kinds of abstract objects, such as propositions and states of affairs.

  • Anti-substrativism: There are no such things as prime matter, bare substrata, or thin particulars.

  • Color subjectivism: The sky is blue, grass is green, and lemons are yellow... yeah right!


  • A means-end orientation: I feel that epistemology should primarily try to settle disputes between different parties concerning what we ought to believe or are justified in believing.

  • Internalism: A corollary of the above. Insofar as externalist analyses of knowledge and justification appeal to facts or processes to which we have no access, they are useless for resolving disputes over what we are justified in believing.

  • A very minimal Foundationalism: Justification has to start somewhere. One's justification derives from properly basic beliefs, but what is properly basic for one person may not be properly basic for another. There is also no reason to assume that properly basic beliefs must be self-evident or immune to revision.

Philosophy of Mind:

  • Phenomenal content internalism: Phenomena such as Churchland's Chimerical Colors show that, at least in some cases, experiences can have qualia and/or phenomenal contents that answer to nothing in "the external world"; and we can't be related, causally or otherwise, to things that aren't there. Personally, I think the case generalizes to other sorts of experience as well.

  • Indirect realism: Even assuming there are no such things as sense data or similar items, we still don't "directly perceive" external objects. This fits in nicely with phenomenal content internalism.

  • First person fallibilism: Things might not seem how they seem to seem.


  • Moral Realism: At least some moral judgments express true propositions.

  • Moral Objectivism: For any given morally evaluable situation, there is a right and a wrong response or set of responses, and whether a given response is right or wrong does not, in general, depend on whether people think it is right or wrong.

  • Non-consequentialism: Morality isn't about maximizing utility, the satisfaction of preferences, the amount intrinsic goodness in the world, or indeed anything. People have duties to each other which in some cases forbid one from bringing about the "greater good."

Style and Method:

  • Style: I try to write clearly and precisely, but as Brand Blanshard showed, these qualities are not the exclusive property of the Analytic tradition.

  • Method: Systematic—I have a broad range of interests and try to find connections between disparate areas of philosophy.

  • Philosophers I admire: Brand Blanshard, A.C. Ewing, Bertrand Russell, Ludwig Wittgenstein, W. V. O. Quine, David Hume, George Berkeley, Alvin Plantinga, Graham Priest, and Patricia Churchland.

Sunday, September 02, 2007

What I sound like

This is a recording made last year of me giving a presentation on Eternalism to the philosophy club at Diablo Valley College in California.

If you're a philosophy blogger and you have a recording of your own voice, I invite you to spread the meme and post your recording on your own blog.