Saturday, July 02, 2011

Tuggy's intellectual shortcuts


DALE SAID:

Steve, it is amazing to me that when I try to un-confuse you on basic logic, I get abused as some kind of arrogant rationalist. But I'll continue, for the sake of the less smug who may read this.

Actually, I hadn’t leveled that accusation. But since you bring it up, yes, there’s a sense in which you’re a rationalist, albeit a rationalist who takes intellectual shortcuts.

You also try to try to bully your opponents into submission. Maybe intimidation works in the classroom, but it has no effect on me.

For a relation to be symmetrical means that if A bears that relation to B, then also B bears it to A. A symmetrical relation doesn't have a direction, as it were.

You admitted at the outset that you know nothing about enantiomorphism.

See here sections 1&2.

I’m already acquainted with the Stanford entry on identity, which, of course, doesn’t address enantiomorphism. Nice bait-n-switch, though.

Geach's position is widely rejected…

I didn’t appeal to Geach, so that’s a red herring.

But I do claim that it is self-evident that there's such thing as =, and that L's Law is self-evident as well, and that these are part of our God-given common sense, and so, really don't need arguing for, for us to rely on them.

Since your unitarian god doesn’t exist, that appeal fails to inspire much confidence. Beyond that, there are several basic problems with your argument:

1. Does Isaian monotheism contradict the Trinity?

Tuggy likes to bandy this charge, but I have yet to see him even begin to rigorously derive that contradiction from Isaian prooftexts. If he’s going to allege a logical contradiction, then that’s a logically stringent allegation. He has to meet to meet a rigorous burden of proof. Just making facile appeals to the law of identity will hardly suffice.

This is what I derive from Isa 40-48:

i) Isaiah logically excludes the possibility that someone without Yahweh’s attributes could be truly divine.

ii) Isaiah logically excludes the possibility that someone with Yahweh’s attributes couldn’t be truly divine.

But I don’t see, by logical implication, how one validly infers from either or both of those propositions that the Trinity contradicts Isaian monotheism.

2. Tuggy has conceded if God is a Trinity, then that’s a necessary truth. In that event, he can’t simply invoke another necessary truth (or what he takes to be another necessary truth) to falsify the Trinity.

If we’re confronted with two apparent necessary truths which apparently contradict each other, what should we do about that? We can’t arbitrarily privilege one necessary truth over another. And a contradiction (real or apparent) doesn’t point in any particular direction regarding the possible resolution.

At best, that shifts to the issue of what’s our degree of warrant for believing that an apparent necessary truth is, in fact a necessary truth? In case of conflict, how do we weigh the comparative warrant for one with the comparative warrant for the other?

The warrant for believing the Trinity is a necessary truth involves the warrant for believing the Bible is inspired, as well as believing the Bible teaches the Trinity.

3. Tuggy says Leibniz law is self-evidently true whereas the Trinity is not self-evidently true.

Keep in mind that he hasn’t actually demonstrated the relevance of Leibniz law to his unitarian prooftexts.

But for the sake of argument, is it self-evident that Leibniz law is a necessary truth? Take the Stanford entry on psychologism:


I think psychologism is wrong, but a philosopher like Tuggy can’t just stipulate that psychologism is self-evidently wrong, for the arguments and counterarguments are quite complicated.

And this illustrates a larger problem for Tuggy: the status of necessary truths is worldview-dependent. Imagine if he were debating W. V. Quine rather than James Anderson. The presumption would be quite different.

On the one hand is the warrant for believing necessary truths like (arguendo) Leibniz law.

On the other hand, the warrant for believing there are no necessary truths given the warrant for believing in things like physicalism, psychologism, eliminative materialism, naturalistic evolution, &c.

I don’t believe those things myself, but as a philosopher, Tuggy can’t act as though his own position is a just a given.

4. Finally, Tuggy’s own position runs afoul of Leibniz law:

4 comments:

  1. Ah, yes, now I'm a bully. Nice. Your constant abuse (e.g. the title of this post) shows that you're not entire secure in your position.

    No, the point about Geach was not a red herring. He's pretty much the only one who's seriously thought about it, who thinks there's no such things as =. The point was: yes, it really it self-evident.

    IF I understand you, you think enantiomorphism is some sort of relation which is a kind of numerical identity which falls short of =. You should be very worried, I think, that no logician takes this view. Most hold that numerical identity has no degrees or kinds.

    "Since your unitarian god doesn’t exist"

    Steve, the point I was making holds of any God - unitarian or trinitarian.

    "Does Isaian monotheism contradict the Trinity?"

    Steve, as you want to read those chapters, the prophet's points are about *divinity* (godhood, deity) - the property of being a god. He is, I think, making a point about true godhood (vs. the old, polytheistic conception), but as you summarize things, he's left the door wide open to others also being divine - so long as they have the sort of deity he spells out. (all provident creator, able to predict future, etc.) But this is an odd reading, for he roundly insists that Yahweh is the only deity, so defined! So, the reader infers, no one other than YHWH is also a deity. You can call that a facile appeal, and you'd like to think there's some undue philosophizing going on there, but that's just common sense. You just refuse to yield, because you're wedded to a theory with three deities - and of course, logically, none of them can be the only true God.

    About necessary truths, no, my point was conditional. IF it's true, then it would have to be a nec truth. But of course, I don't think it is true. The evidence for it largely melts away on close examination. If you're in the grip of a trinitarian reading, then yes, you may find yourself thinking that there's a Trinity (however you define that) and also, there's something about as obvious as 2+2=4 and which seems inconsistent with the Trinity. Then, you'd better read Anderson's book - he's the only trinitarian who really addresses this situation. Yes, it's about comparing degrees of warrant, but also about the notion of "defeaters," which James well explains.

    "he hasn’t actually demonstrated the relevance of Leibniz law to his unitarian prooftexts."

    L's Law, if true, applies to any entity. This, for it to be applicable to Is. all we have to presuppose is that "Yahweh" there refers to an entity. And, it seems to. You'd have to argue that it's what logicians call a "plural referring term" to get out of this.

    "status of necessary truths is worldview-dependent"

    I view this is a desperate defense, Steve. What you're saying is that somebody out there, somebody smart, believes something which, somehow, would keep my argument from going through. Sure the odd logician like Quine, or your common confused postmodernist, may deny that any truths are necessary. Well, some have denied that sense-perception is basically reliable, or that there is a real physical cosmos. But the existence of such doesn't much diminish your confidence in e.g. sight, or that there is a real cosmos. And rightly so!

    So I've emphasized once or twice in this discussion, that you too assume the truth of L's Law, as you must, having common sense. What's trouble for you is not what the dastardly Tuggy asserts, but rather what logically follows from what you're already committed to.

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  2. DALE SAID:

    "I view this is a desperate defense, Steve. What you're saying is that somebody out there, somebody smart, believes something which, somehow, would keep my argument from going through. Sure the odd logician like Quine, or your common confused postmodernist, may deny that any truths are necessary. Well, some have denied that sense-perception is basically reliable, or that there is a real physical cosmos. But the existence of such doesn't much diminish your confidence in e.g. sight, or that there is a real cosmos. And rightly so!"

    And attempting to keep you honest, which isn't easy. You said your position was "self-evident."

    Is that claim philosophically true or false? I cited two counterexamples from Quine and psychologism.

    And I notice that you're not presenting an actual counterargument.

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  3. You said your position was "self-evident."

    Which position... that there's such thing as =, or that some truths are necessary (true to matter what, such that they can't be false)?

    Either way, yes, I think both are self-evident. i.e. when a normal adult human carefully considers it, it strongly seems true.

    Yes, it is a sad fact for humanity that for any truth, no matter how strongly it seems to us, we can find, if we search hard, some very smart person who has denied it.

    People will deny just about anything to save a pet theory. Philosophers call this "biting the bullet" - a case like: it seems obvious that P. But, if my theory is right, -P. So, I say -P!

    Again, sometimes it isn't clear that the person is saving a pet theory. Sometimes we just don't know why the intuitions differ.

    In general, it is very hard to argue for something which is self-evident, because there's nothing which is *more* clearly so.

    And it's also hard to argue *that* some claim is self-evident. One in most cases has to just invite the opponent to consider the matter for himself. Or if he sees some error that would explain the false appearance, he should say what it is.

    All of this procedure I'm explaining, by the way, comes from two great Reformed Christian philosophers: Thomas Reid (d. 1796) and Alvin Plantinga. It's based on a trust in the goodness of God, and viewing our basic epistemic faculties as made by his hand, and it is consciously opposed to "rationalist" methodology like Descartes, Leibniz, and Spinoza (long story why) as well as any extreme empiricist view (e.g. Hume).

    In any case, be clear that I'm not taking this shortcut: claiming that my whole theology is self-evident, or that my reading of, e.g. Isaiah is so. I don't think that; I do have arguments for those views. Of course, whenever you argue, you pretty quickly run into claims which seems true, and which seem that they don't need to be argued for, and would be hard to argue for.

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  4. "It's based on a trust in the goodness of God, and viewing our basic epistemic faculties as made by his hand,"

    This could mislead; let me clarify. The view is that it is self-evident that our epistemic (belief-forming) faculties are *generally* reliable. This is consistent with, and arguably buttressed by our trust in God, but it is in their (and my) view something people reasonably believe on autopilot even if they've never thought about God. It's a very subtle epistemology.

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