TheOtherDave’s suggestion (in so far as I understand it) clearly differs from what I mean when I talk about existence
Awesome! I love clear differences. Can you give me an example of some thing that exists, for which my proposed tabooing of “existence” doesn’t apply? Or, conversely, of something for which my proposed tabooing applies, but which doesn’t exist?
With the caveat that I might not fully understand your proposed tabooing, here’s my concern with it. There are models which are empirically equivalent, yet disagree on the furniture of the world. As far as I can see, your tabooing, with its emphasis on predictive success, cannot distinguish between the ontological claims made by these models. I think one can. For instance, even if two theories make identical predictions, I would say the right move would be adopt the ontology of the simpler of the two.
Perhaps I can expand on my proposed tabooing. Instead of just “The set of Fs is non-empty”, make it “The set of Fs is non-empty according to our best physical theory”, where the “best physical theory” is determined not just by empirical success but by extra-empirical virtues such as simplicity.
Wrt your revised tabooing… that has the odd property that entities come into existence and cease existing as our physical theories change. I guess I’m OK with that… e.g., if you really want to say that quarks didn’t exist in 1492, but that quarks in 1492 now existed, I won’t argue, but it does seem like an odd way to talk.
Wrt your concern… hrm. Let me try to be more specific.
So, I have two empirically equivalent models M1 and M2, which make different ontological claims but predict the same experiences in a range of contexts C (as C approaches infinity). Let us say that M1 asserts the existence of X, and M2 asserts instead the existence of Y, and X is simpler than Y. I also have a set of experiences E1, on the basis of which I adopt M1 as my model (for several reasons, including the fact that my experiences have led me to prefer simpler models). Based on this, I predict that my future experiences E2 will be consistent with the past experiences E1 which led me to to put X in my model in the first place, which include the experiences that led me to endorse Occam’s Razor. If that prediction proves false—that is, if I have experiences that are inconsistent with that—I should reduce my confidence in the existence of X. If it proves true—that is, I have no experiences that are inconsistent with that—I should remain confident.
Is that example consistent with your understanding of how my proposed tabooing works?
If so, can you say more about your concern? Because it seems to me I am perfectly able to distinguish between M1 and M2 (and choose M1, insofar as I embrace Occam’s Razor) with this understanding of existence.
Wrt your revised tabooing… that has the odd property that entities come into existence and cease existing as our physical theories change. I guess I’m OK with that… e.g., if you really want to say that quarks didn’t exist in 1492, but that quarks in 1492 now existed, I won’t argue, but it does seem like an odd way to talk.
The tabooing is not supposed to be an analysis of what makes things exist; it is an analysis of when we are justified in believing something exists. It’s a criterion for ontological commitment, not ontology. I took it that this was what your tabooing was supposed to convey as well, since surely there can be things that exist that don’t feature in our models. Or maybe you don’t think so?
To get an actual criterion of ontology rather than just a criterion of ontological commitment, replace “our best physical theory” with “the best physical theory”, which may be one that nobody ever discovers.
Based on this, I predict that my future experiences E2 will be consistent with the past experiences E1 which led me to to put X in my model in the first place, which include the experiences that led me to endorse Occam’s Razor.
Ah, I see. This makes your view more congenial to me. Although it still depends on what you mean by consistent. If one of my future experiences is the discovery of an even simpler empirically adequate theory, then presumably you would say that that experience is in some sense inconsistent with E1? If yes, then I don’t think there is much of a difference between your proposal and mine.
I took it that this was what your tabooing was supposed to convey as well,
I understood the point to be to replace the phrase “X exists” with an expression of what we’re trying to convey about the world when we say “X exists.” Which might conceivably be identical to what we’re trying to convey about the world when we say “I’m justified in believing X exists”, depending on what we want to say about when a belief is justified, but if we allow for things that happen to be true but are nevertheless not justified beliefs (which I do) then they aren’t identical.
But, sure, if we’re talking about epistemology rather than ontology, then my objection about quarks is irrelevant.
If one of my future experiences is the discovery of an even simpler empirically adequate theory, then presumably you would say that that experience is in some sense inconsistent with E1? If yes, then I don’t think there is much of a difference between your proposal and mine.
If E2 includes experiences (such as that theory) that lead you to reject the model E1 led you to embrace, then yes, I would say E2 and E1 are inconsistent. (In the sense that they require that the world be two mutually exclusive ways. I’m not really sure what other sense of “inconsistent” there is.)
If yes, then I don’t think there is much of a difference between your proposal and mine.
Awesome! I love clear differences.
Can you give me an example of some thing that exists, for which my proposed tabooing of “existence” doesn’t apply? Or, conversely, of something for which my proposed tabooing applies, but which doesn’t exist?
With the caveat that I might not fully understand your proposed tabooing, here’s my concern with it. There are models which are empirically equivalent, yet disagree on the furniture of the world. As far as I can see, your tabooing, with its emphasis on predictive success, cannot distinguish between the ontological claims made by these models. I think one can. For instance, even if two theories make identical predictions, I would say the right move would be adopt the ontology of the simpler of the two.
Perhaps I can expand on my proposed tabooing. Instead of just “The set of Fs is non-empty”, make it “The set of Fs is non-empty according to our best physical theory”, where the “best physical theory” is determined not just by empirical success but by extra-empirical virtues such as simplicity.
Wrt your revised tabooing… that has the odd property that entities come into existence and cease existing as our physical theories change. I guess I’m OK with that… e.g., if you really want to say that quarks didn’t exist in 1492, but that quarks in 1492 now existed, I won’t argue, but it does seem like an odd way to talk.
Wrt your concern… hrm. Let me try to be more specific.
So, I have two empirically equivalent models M1 and M2, which make different ontological claims but predict the same experiences in a range of contexts C (as C approaches infinity). Let us say that M1 asserts the existence of X, and M2 asserts instead the existence of Y, and X is simpler than Y. I also have a set of experiences E1, on the basis of which I adopt M1 as my model (for several reasons, including the fact that my experiences have led me to prefer simpler models). Based on this, I predict that my future experiences E2 will be consistent with the past experiences E1 which led me to to put X in my model in the first place, which include the experiences that led me to endorse Occam’s Razor. If that prediction proves false—that is, if I have experiences that are inconsistent with that—I should reduce my confidence in the existence of X. If it proves true—that is, I have no experiences that are inconsistent with that—I should remain confident.
Is that example consistent with your understanding of how my proposed tabooing works?
If so, can you say more about your concern? Because it seems to me I am perfectly able to distinguish between M1 and M2 (and choose M1, insofar as I embrace Occam’s Razor) with this understanding of existence.
The tabooing is not supposed to be an analysis of what makes things exist; it is an analysis of when we are justified in believing something exists. It’s a criterion for ontological commitment, not ontology. I took it that this was what your tabooing was supposed to convey as well, since surely there can be things that exist that don’t feature in our models. Or maybe you don’t think so?
To get an actual criterion of ontology rather than just a criterion of ontological commitment, replace “our best physical theory” with “the best physical theory”, which may be one that nobody ever discovers.
Ah, I see. This makes your view more congenial to me. Although it still depends on what you mean by consistent. If one of my future experiences is the discovery of an even simpler empirically adequate theory, then presumably you would say that that experience is in some sense inconsistent with E1? If yes, then I don’t think there is much of a difference between your proposal and mine.
I understood the point to be to replace the phrase “X exists” with an expression of what we’re trying to convey about the world when we say “X exists.” Which might conceivably be identical to what we’re trying to convey about the world when we say “I’m justified in believing X exists”, depending on what we want to say about when a belief is justified, but if we allow for things that happen to be true but are nevertheless not justified beliefs (which I do) then they aren’t identical.
But, sure, if we’re talking about epistemology rather than ontology, then my objection about quarks is irrelevant.
If E2 includes experiences (such as that theory) that lead you to reject the model E1 led you to embrace, then yes, I would say E2 and E1 are inconsistent. (In the sense that they require that the world be two mutually exclusive ways. I’m not really sure what other sense of “inconsistent” there is.)
All right.