One of Dale Tuggy's dilemmas is his unsuccessful attempt to compartmentalize numerical identity. He makes allowances for personal identity which he disallows in the case of numerical identity. He's too bullheaded to appreciate that personal identity is just a special case of numerical identity. Numerical identity is the general principle, of which personal identity is one example.
For instance, Tuggy himself seems to think personal identity requires numerical identity. Tuggy the militant unitarian is numerically the same person as Tuggy the social Trinitarian. Yet Tuggy is a methodist about numerical identity, but a particularist about personal identity. Where numerical identity is concerned, he begins with criteria: Leibniz's Law! A necessary truth! Or his a priori stipulation that "numerical identity doesn't come in degrees."
But where personal identity is concerned, he begins with examples: "Don’t things change? e.g. Last year you weighed 200, and now you weight 210 lbs. But does this mean that the you of 2010 is not numerically the same as the you of 2011? Ridiculous! Things can qualitatively change while remaining numerically the same. That’s just common sense."
Here he just stipulates that qualitative change is consistent with numerical identity because "that's just common sense." So he has two contrary standards for defining identity. And yet he tries to merge the two when it serves his purpose.
Consider two hypotheticals:
i) What would I be like if my mother had died when I was five?
ii) What would I be like if I were a giraffe?
The first hypothetical is realistic. We may not know enough to answer that question, but that was possible, and if it happened, I would turn out differently.
But the second hypothetical is basically nonsense. A giraffe is so different from a human that it wouldn't be the same individual in any appreciable sense.
That's why a standard move in discussions of transworld identity is to take the nearest possible world as the frame of reference. A possible world most like the real world. But that means counterfactual identity is based on similarity rather than sameness. And similarity is a matter of degree. Degrees of similarity and dissimilarity.
That's why the first hypothetical is realistic. It posits that I and my counterpart have the same personal history up to the age of 5, at which point, due to a family tragedy, our paths begin to diverge. But because we were the same person with the same history up to that point, and because we remain human, have the same surviving parent, and so forth, there's a meaningful basis of comparison. Those could be alternate outcomes for the same individual.
By contrast, a giraffe is so unlike a human that a giraffe can't be your counterpart in a possible world. There is no sense in which you could be identical to a giraffe.
But if counterfactual identity is a matter of degree, then why not diachronic identity? Suppose we recast the counterfactual scenario in chronological terms: What would I be like if I turned into a giraffe tomorrow? Here issues of diachronic and transworld identity intersect. It's about past and future identity, as well as counterfactual identity. And the comparison fails for the same reason. Lack of adequate, salient similarity.
Tuggy's objection to the Trinity is especially ironic considering the fact that he maintains a temporalist view of God. So for Tuggy, personal identity and diachronic identity intersect in God's case no less than man's case. Tuggy's God undergoes change. And change is a kind of difference. Clearly, then, there's a sense in which Tuggy's God is not uniformly the same God from t1 to t2.
Likewise, Tuggy is a freewill theist. Tuggy's God has counterparts in possible worlds, where God said or did something different. Where God's experience is different. Clearly, then, there's a sense in which Tuggy's God is not uniformly the same from w1 to w2.
Even in reference to divine personal identity, Tuggy makes allowance for differentia concerning that individual. So why does he refuse to make allowance for differentia concering the Trinity? Why does he measure the Trinity by the yardstick of strict identity, but use a rubber ruler for his own God when it comes to transworld identity or identity over time? Flexible theories of identity for unitarian open theism, but inflexible theories of identity for Trinitarian theism.
Sure, Tuggy can dictate that certain kinds of change or difference are somehow consistent with numerical identity; sure, he can dictate that certain kinds of change or difference are consistent with his denial that numerical identity admits degrees of identity, but is there anything beyond his arbitrary stipulation to show how that's consistent?
He can attempt to distinguish between intrinsic and extrinsic properties, but that presumes rather that proves consistency with numerical identity. For unless you can already establish that the intrinsic/extrinsic distinction is compatible with numerical identity, you can't invoke that distinction to salvage numerical identity. Whether distinctions like that are consonant with strict identity is the very issue in dispute. And if that's consistent with numerical identical, why not other kinds of differentia?
This is a central tension in his position. He doesn't begin with Leibniz's law when he clears space for personal identity. When push comes to shove, he makes ad hoc modifications to Leibniz's law to accommodate whatever personal identity demands. His unyielding definition of numerical identity in relation to the Trinity becomes very yielding when he turns to the ambiguities of personal identity. He regards the "law of identity" as a necessary truth, but contingent truths shape his view of personal identity. As a result, you notice the gearbox smoke and grind when he tries to mesh the two.
There are philosophers like McTaggart who are far more uncompromising when it comes to strict identity. McTaggart is a consistent methodist. Tuggy, by contrast, has a makeshift position. He's a methodist when attacking the Trinity, but a particularist on personal identity. Yet his views on personal identity infect his views on numerical identity. By introducing fudge factors into personal identity, his theory of numerical identity becomes chocolate-coated in the process. There's no uniform principle driving his theories of identity.
Steve, a core point you're not grasping is that most agree that "x and y are the same F" where F is some sortal concept, is to be analyzed as: x is an F, y is an F, and x=y. So, if Paul and Saul are the same man, this means that Paul is a man, Saul is a man, and Paul = Saul. This is why "personal identity requires numerical identity" - that isn't some sort of Tuggyism, rather, it follows from this analysis.
ReplyDeleteThe only people who disagree with this analysis are relative identity theorists. But most who look into such theories reject them for non-theological reasons. http://plato.stanford.edu/entries/trinity/#RelIde By all means, check these out, and see if these prices are worth paying, in order to uphold the claims of the Athanasian creed.
The suggestion that there are kinds of = is idiosyncratic. Maybe you're gesturing at something like Geach's claim that at bottom there is no =, but there are only relations like being the same man as, being the same planet as, being the same god as, etc. - where these are taken as basic, not analyzable as above. Those who are clear about = think that it doesn't come in varieties.
Same with degrees. If you're thinking of something that comes in degrees, you're surely thinking of some other relation, one that is identity-like somehow. Often, this is qualitative sameness / similarity.
Dale,
DeleteYou keep missing the point. Is that because you're simply unable to grasp the point?
You seem to think my argument requires me to challenged your definition of numerical identity. Not so. I can grant your definition for the sake of argument.
The problem is the relationship between numerical identity, thus defined, and personal identity. It's the tension between the two that generates a problem for your position.
Typically, you simply fail to event directly engage what I said about degrees in relation to counterfactual identity, where the nearest-possible-world forms the basis of comparison. In that context, "nearest" or "closest" means "most like." So that's identity grounded in similarity rather than sameness. Indeed, if they were the same in every respect, it wouldn't be counterfactual.
You blow past that as unacceptable without even attempting to refute the explanation. This isn't my idiosyncratic interpretation. I'm drawing attention to standard expositions of transworld identity. You haven't begun to show how that's not an implication of the example.
Steve,
Delete"The problem is the relationship between numerical identity, thus defined, and personal identity."
You're still not getting the point of my first paragraph above.
"identity grounded in similarity"
No, sorry. I just don't have time to explain the whole transworld identity thing to you. You'll have to read up.
I've obviously studied the literature on transworld identity. And I don't need somebody as incompetent as you to explain it to me.
Delete" two contrary standards for defining identity. And yet he tries to merge the two when it serves his purpose. "
ReplyDeleteNo, I don't think identity is definable. It is a basic, undefinable concept. I think you're pointing at identity at a time, which requires no qualitative difference, and identity at two times, which allows for non-essential differences. But this is just because I think this is possible: something changes. Of course, you do too!
"What would I be like if I were a giraffe?"
Nonsense, yes, not in having no meaning, but in being a counterpossible - a hypothetical about a situation that is absolutely impossible.
"if counterfactual identity is a matter of degree"
Steve, no one thinks this. If all we have are similarities in counterparts across worlds, that is to say that there is no transworld *identity*, but only what David Lewis calls "counterpart" relations between you and other Steve-like beings in other "worlds" (possible situations). But this is against common sense. We all think it is true, e.g. that *I* could've eaten one more french fry the other day. The alternative is that all things are "world-bound", that things have all their properties essentially.
"there's a sense in which Tuggy's God is not uniformly the same God from t1 to t2."
A trivial point. That is just to say that he changes in some non-essential respects. But he remains one and the same, self-identical being throughout all of time.
"No, I don't think identity is definable."
DeleteWhat are formulations of Leibniz's law if not definitions of identity or efforts to rigorously explicate the concept?
"Steve, no one thinks this. If all we have are similarities in counterparts across worlds, that is to say that there is no transworld *identity*, but only what David Lewis calls 'counterpart' relations between you and other Steve-like beings in other 'worlds' (possible situations). But this is against common sense. We all think it is true, e.g. that *I* could've eaten one more french fry the other day."
Dale, you're not arguing for your claims. Your modus operandi is to *assert* that counterfactuals are consistent with numerical identity. You don't begin to *demonstrate* how that possible given your definition of numerical identity.
Once again, you fall back on "common sense," but as I've repeatedly pointed out to you, a common sense criterion is logically unrelated to a formal, abstract definition of numerical identity. You didn't derive your definition of common sense from your definition of numerical identity, and you didn't derive your definition of numerical identity from common sense. At best, common sense is just an appeal to contingent experience. That's not a "necessary truth."
"A trivial point. That is just to say that he changes in some non-essential respects. But he remains one and the same, self-identical being throughout all of time."
An all-too-typical example of Dale resolving a point of tension by *asserting* that there's no real point of tension.
i) To claim that numerical identity is compatible with "changes in some non-essential respects" takes for granted the very assumption in dispute.
ii) Notice, moreover, that he doesn't show how those concessions and qualifications follow from a rigorous view of numerical identity. He doesn't take a formal definition of numerical identity as his starting-point, then demonstrate how that makes allowance for "non-essential changes." He doesn't show how "non-essential changes" are built into the definition of numerical identity.
Instead, he merely stipulates that these two things are harmonious.
"What are formulations of Leibniz's law if not definitions of identity or efforts to rigorously explicate the concept? "
DeleteAttempts to express a self-evident truth.
Again, = isn't really explicable, or definable in terms of anything else. It can be described, as I have, and examples can be given in how we all reason about it.
Steve, when you're confused on a topic, it can sometimes seem that the person you're arguing with is confused. You ought to see this in the present case. But instead, you just accuse me of ignoring the point. Again, you must read up.
Dale,
DeleteIf you think numerical identity is unanalyzable because it's "basic concept," then it can't even be formulated.
To say identity isn't explicable or definable in terms of anything else is a peculiar claim when it's partially definable by its opposite (nonidentity) and vice versa. These are mutually supplementary concepts.
"Why does he measure the Trinity by the yardstick of strict identity, but use a rubber ruler for his own God when it comes to transworld identity or identity over time?"
ReplyDeleteSteve, I know it's just too tempting to think you've caught me in some contradiction here, but there is none. In all my discussions of the Trinity, except when discussing the relative identity theories, I'm using the plain old concept of =, as taught in any college logic text book. It is the relation which is necessarily transitive, reflexive, and asymmetrical, and which "forces" indiscernibility. Look it up.
"This is a central tension in his position. He doesn't begin with Leibniz's law when he clears space for personal identity. When push comes to shove, he makes ad hoc modifications to Leibniz's law to accommodate whatever personal identity demands."
Sorry, but you haven't shown any tension at all. About the ad hoc "modifications" - the way I formulate that principle in some of my blog posts - they're simply not ad hoc. They're based on this intuition that everyone has: it is impossible that a thing intrinsically be and not be some way at some time.
If you want to argue that intrinsic change is impossible, be my guest. If you'd like to deny the intuition just stated, go ahead. If you want to deny that there is transworld identity, go ahead. Those would be ways to attack my views. It'd also be attacking common sense, equally.
I know that you badly, badly want to find some way that I'm "cheating" when it comes to the Trinity, or that my objections are based on idiosyncratic speculations about identity. Sorry to disappoint. You should be aware that trinitarian Christian philosophers, with the exception of a minority (Baber, Geach, Martinich) simply accept the standard logic of identity, along with the Indiscernibility of Identicals. They adjust their Trinity theories to fit these truths, as they do to fit, say, the laws of logic. The minority goes for relative identity, in a couple of different but related ways. Rea's approach is best developed, but has a lot of other costs.
If I were making some basic mistake about identity, or was insisting on some weird speculation about identity just to stick it to Trinity theories, you can be assured that my fellow Christian philosophers would have thoroughly called me out on it by now. But in fact, I only get protests from the relative identity crowd. Again, do check them out, to see if that seems like a good way to self-consistently parse the standard catholic Trinity formulas.
Let me end by recommending this source, by philosopher John Hawthorne, on identity: http://trinities.org/blog/on-numerical-sameness-identity-absolute-identity/
"I'm using the plain old concept of =, as taught in any college logic text book. It is the relation which is necessarily transitive, reflexive, and asymmetrical, and which 'forces' indiscernibility. Look it up."
DeleteDale, you never miss a chance to miss the point. Is that because you're unable to grasp the issue? The question at issue isn't simply how you define numerical identity in isolation, but whether that's compatible with personal identity. Try hard to keep two ideas in your mind at one time: the question at issue is the *relationship* between these two things.
"They're based on this intuition that everyone has: it is impossible that a thing intrinsically be and not be some way at some time."
Dale, there's more than one intuition in play. There are intuitions about numerical identity, identity over time, and transworld identity. The more inflexible the definition of numerical identity, the greater the strain that puts on numerical identity. How you map the former onto the latter. That's the challenge.
Now, you throw in the weasel word "intrinsically." But is that harmonizing maneuver a universal intuition? What about Buddhist metaphysics?
"If you want to argue that intrinsic change is impossible, be my guest. If you'd like to deny the intuition just stated, go ahead. If you want to deny that there is transworld identity, go ahead. Those would be ways to attack my views. It'd also be attacking common sense, equally."
Once again, Dale, are you just too slow on the uptake to grasp the actual state of the argument? The question at issue isn't what I personally affirm or deny, but whether you're ignoring and glossing over major tensions between different principles–all of which you accept, but leave in tension.
Anyone who's studied philosophical debates concerning personal identity in relation to diachronic identity or counterfactual identity will see that philosophers struggle with deep and difficult tensions between numerical identity and diachronic and/or counterfactual identity. That's not just me making this stuff up.
Different philosophers propose different strategies for attempting to relieve the tension. Some cut the knot by denying change or denying the truth-value of counterfactuals. Yet you act as if these aren't real, abiding issues in philosophy.
"Sorry to disappoint. You should be aware that trinitarian Christian philosophers, with the exception of a minority (Baber, Geach, Martinich) simply accept the standard logic of identity, along with the Indiscernibility of Identicals."
i) Notice that Dale hasn't shown how the "standard logic of identity" along with " the Indiscernibility of Identicals" can be squared with paradigm examples that create problems for his glib appeal.
Dale's attack on the Trinity depends on his definition of numerical identity. Yet he papers over fundamental counterexamples with lots of rhetorical hand-waving.
ii) Keep in mind that I haven't conceded that the Trinity is contrary to numerical identity. Indeed, I've noted that enantiomorphic symmetries, with their systematic mapping, comport with Leibniz's law even though enantiomorphic symmetries aren't interchangeable.
Steve, you're right about this: someone is missing the point here. It *could* be the PhD in Philosophy who has taught courses in metaphysics and logic. But there is another possibility...
Delete"I haven't conceded that the Trinity is contrary to numerical identity"
This is not an objection that I've made, and it makes no sense. = is just a concept, a basic one. It's not a claim, and so will not clash with any theory. You are so hot to defend your theology, that you're attacking a fundamental and indispensable concept as if it were a claim and a theory.
"Dale's attack on the Trinity depends on his definition of numerical identity."
See, you think that there's a definition there, and a controversial claim. You're just not clear on what is going on. Sorry, I'm done. I'm going to let you conclude that I'm just dumb or afraid to counter your mighty arguments.
"Steve, you're right about this: someone is missing the point here. It *could* be the PhD in Philosophy who has taught courses in metaphysics and logic."
DeleteDale, trying to pull rank on me is counterproductive. It's easy to pull rank on you. There are Trinitarian philosophers (e.g. Plantinga, Alex Pruss, Peter van Inwagen, Bob Adams) who are far more distinguished than you.
"See, you think that there's a definition there, and a controversial claim. You're just not clear on what is going on."
Dale, you're hopelessly silly. Formulations of the Leibniz's law, which you constantly appeal to, are assuredly attempts to formally define or explicate the concept of identity.
And, yes, the relationship between numerical identity and personal identity is demonstrably controversial.