I want to briefly comment on and recommend this paper by Takeshi Yagisawa called "Modal Realism with Modal Tense" (HT: OPP). It explores the parallels between modal and temporal metaphysics, and suggests that modal realists would benefit from treating the possible and the actual as tenses, in the manner of past and present tense, respectively.
Modal realism can create terminological and conceptual ambiguities which leave it vulnerable to criticism. If we speak of a (metaphysically) possible talking donkey and an actual mute donkey, how is it that the possible donkey is “real” if it isn’t “actual”? So, for the verb denoting reality we’re using (e.g. “is” or “exists”), we should consider creating two modal tenses. The possibility tense is an analog of the past tense; the actuality tense is an analog of the present tense. There is much less ambiguity or confusion when we say “dinosaurs existed”. Existing in the past tense is something we have an intuitive feel for (this is not to say philosophers don’t argue about the ontological status of past, present and future events/objects -- they do it all the time -- it’s just that the modality discussion suffers in comparison due to lacking the built-in toolkit of having tenses for words like “exist”).
There are many more subtleties to this idea than I will mention here and Yagisawa unpacks and presents them carefully. An interesting idea he discusses is a comparison of 2 approaches to modality to 2 parallel views of temporality as follows. If one views the possible and actual modes of reality in an even-handed or egalitarian fashion in the manner of David Lewis, this is analogous to the 4-dimensional or eternalist view of temporality, where different points in time all exist in an even-handed way. If one views the actual as deserving to be called “real” and wish to downgrade the reality of the possible (as in the view traditionally called “Actualism”), this is in the same spirit as presentism, which likewise displays a “chauvinism” in viewing the present as having an exclusive claim on reality.
I have been using the terms abstract and concrete to characterize the possibilities and the actualized events of our world, respectively. I think this is still OK as long as I can communicate it with some context. The appeal of using modal tenses is that it provides another way to introduce a primitive distinction to characterize the possible and actual without requiring either total even-handedness or a deflation of the possible. This was a thought-provoking paper.
Tuesday, January 30, 2007
Wednesday, January 24, 2007
Science Blog Anthology
Bora Zivkovic (coturnix) from A Blog Around the Clock put together a very nice collection of science blog posts. I may be a little old fashioned, but I appreciated even the posts I already had read a bit better in book form, seated in my favorite chair.
Tuesday, January 23, 2007
Re-reading Pirsig
From notes in an old journal, I know I first read Robert M. Pirsig’s Zen and the Art of Motorcycle Maintenance in 1982 (it was first published in 1974). I read his second book, Lila, shortly after it came out in 1991. I recently re-read them, and I have a greater appreciation for his (idiosyncratically expressed) philosophy than I had the first time through. In fact, I think he was pretty much on the right track. (BTW, I read a recent interview with Pirsig here -- hat tip to the Market Metaphysics blog.)
What I originally absorbed from “Zen” (philosophically speaking – I should say it is also a compelling novel) was mostly negative: Pirsig saw fit to basically indict all Western philosophy. Starting with Plato and especially Aristotle, those darn philosophers broke down the ineffable mystic oneness of reality into cold bloodless conceptual categorizations and led us astray. Given my own youthful contemporaneous interest in eastern philosophy, I embraced the criticism, but didn’t really grasp any positive import from Pirsig’s proposal of “Quality” as the supreme notion: I would have been just as happy with Zen, Tao or Brahman.
Now, by the time I read Lila, I was on the same page with Pirsig regarding the deep problem of the subject-object ontological division, which seemed to lie at the root of many seemingly intractable philosophical difficulties (most obviously the mind/body problem). Around this time I was reading Continental philosophers who I thought had taken on the challenge of bridging this divide (most notably Heidegger and Merleau-Ponty). The idea I was exploring was one of activity or process as the central entity. Pirsig seemed to agree, although it seems again that Pirsig’s specific talk of “dynamic quality” or “patterns of value” still didn’t resonate. (Also, I should digress to mention that Lila is much less compelling as a novel compared to “Zen”, and much of the book consists of social commentary/cultural criticism which doesn’t inevitably follow from the philosophy IMHO).
In the intervening years since 1991, the most interesting part of philosophy to me was the debate over conscious experience in the philosophy of mind. The fact that I believe the debate points toward a panexperientialist solution is a touchstone for a lot of the discussion on this blog. And it is the idea of placing experience (or a network of experiential events) into the center of metaphysics which I think shows a tie to what Pirsig was talking about.
To see this, let’s first shift from “Quality” to “value”, which Pirsig endorses in Lila: In chapter 4 (on p.58 of my 1991 hardcover), he says “Quality was value. They were the same thing.” Well, value is inherent in an experience; it is an aspect of the intrinsically intentional first person participation in an event. Pirsig then actually identifies value with experience on p. 66: “It is an experience” (Emphasis original). Value, according to him, exists in the interaction – it is more fundamental than the subject-object division, it is “Between the subject and object…” For me, at various subsequent points in the text, if I substitute the term experience or “experiential event” for quality or value, things begin to make a lot of sense.
At various points in Lila, Pirsig explains how he thinks his perspective points to solutions to various philosophical conundrums. For example, in Chapter 8 (p.102-3): “To say ‘A causes B’ or to say that B ‘values precondition A’ is to say the same thing.” The way I put it (inspired by Gregg Rosenberg and an interpretation of QM): in addition to the effective/dispositional side of a causal event, there is equally an experiential/receptive side. Further on in the chapter he criticizes substance as a derivative and misleading ontological category, again asserting the primacy of “value”, in tune with the endorsement of an event ontology here on the blog.
And of course, arguing that value (or dynamic quality) is ontologically prior to its division into subject and object directly addresses the origin of the mind/body problem in the same spirit as panexperientialism. As he says late in the book (Ch 29, p. 365): “Pure experience cannot be called either physical or psychical: it logically precedes this distinction.”
What I originally absorbed from “Zen” (philosophically speaking – I should say it is also a compelling novel) was mostly negative: Pirsig saw fit to basically indict all Western philosophy. Starting with Plato and especially Aristotle, those darn philosophers broke down the ineffable mystic oneness of reality into cold bloodless conceptual categorizations and led us astray. Given my own youthful contemporaneous interest in eastern philosophy, I embraced the criticism, but didn’t really grasp any positive import from Pirsig’s proposal of “Quality” as the supreme notion: I would have been just as happy with Zen, Tao or Brahman.
Now, by the time I read Lila, I was on the same page with Pirsig regarding the deep problem of the subject-object ontological division, which seemed to lie at the root of many seemingly intractable philosophical difficulties (most obviously the mind/body problem). Around this time I was reading Continental philosophers who I thought had taken on the challenge of bridging this divide (most notably Heidegger and Merleau-Ponty). The idea I was exploring was one of activity or process as the central entity. Pirsig seemed to agree, although it seems again that Pirsig’s specific talk of “dynamic quality” or “patterns of value” still didn’t resonate. (Also, I should digress to mention that Lila is much less compelling as a novel compared to “Zen”, and much of the book consists of social commentary/cultural criticism which doesn’t inevitably follow from the philosophy IMHO).
In the intervening years since 1991, the most interesting part of philosophy to me was the debate over conscious experience in the philosophy of mind. The fact that I believe the debate points toward a panexperientialist solution is a touchstone for a lot of the discussion on this blog. And it is the idea of placing experience (or a network of experiential events) into the center of metaphysics which I think shows a tie to what Pirsig was talking about.
To see this, let’s first shift from “Quality” to “value”, which Pirsig endorses in Lila: In chapter 4 (on p.58 of my 1991 hardcover), he says “Quality was value. They were the same thing.” Well, value is inherent in an experience; it is an aspect of the intrinsically intentional first person participation in an event. Pirsig then actually identifies value with experience on p. 66: “It is an experience” (Emphasis original). Value, according to him, exists in the interaction – it is more fundamental than the subject-object division, it is “Between the subject and object…” For me, at various subsequent points in the text, if I substitute the term experience or “experiential event” for quality or value, things begin to make a lot of sense.
At various points in Lila, Pirsig explains how he thinks his perspective points to solutions to various philosophical conundrums. For example, in Chapter 8 (p.102-3): “To say ‘A causes B’ or to say that B ‘values precondition A’ is to say the same thing.” The way I put it (inspired by Gregg Rosenberg and an interpretation of QM): in addition to the effective/dispositional side of a causal event, there is equally an experiential/receptive side. Further on in the chapter he criticizes substance as a derivative and misleading ontological category, again asserting the primacy of “value”, in tune with the endorsement of an event ontology here on the blog.
And of course, arguing that value (or dynamic quality) is ontologically prior to its division into subject and object directly addresses the origin of the mind/body problem in the same spirit as panexperientialism. As he says late in the book (Ch 29, p. 365): “Pure experience cannot be called either physical or psychical: it logically precedes this distinction.”
Wednesday, January 10, 2007
The Limit of the Bayesian Interpretation
I read the paper “Subjective probability and quantum certainty” by Carleton Caves, Christopher Fuchs, and Rüdiger Schack; this is the latest in a series of papers which make a compelling case for the superiority of a Bayesian or subjective interpretation of quantum probabilities. (For a discussion of another paper in the same spirit, see this prior post). To bring the point home, this particular paper features the discussion of quantum experiments with a certain outcome: the authors show that this outcome is to be interpreted as a certainty of epistemic belief on the part of the observer, not an objective certainty.
While I am persuaded that the Bayesian interpretation does win out over attempts to see quantum probabilities (or quantum states) as fully objective, there is a limit to how satisfying the analysis can be as an overall ontological interpretation of QM.
Here's a very brief summary. The authors note the fundamental category distinction in Bayesian probability theory between probabilities and facts. Probabilities cannot be reduced to facts; facts (the truth values of propositions) are used to update prior probability assignments.
In the context of a QM experimental setup, the quantum states are “catalogues of probabilities for measurement outcomes...” which “…summarize an agent’s degrees of belief about the potential outcomes of quantum measurements.” What might be less obvious is how to correctly interpret the preparation procedure. According to a common Copenhagen reading of the situation, the preparation procedure is described classically and the facts about the procedure determine the quantum state. (To reiterate, in the Bayesian interpretation probabilities can never be wholly determined by facts).
The authors set out to show that “the posterior state always depends on the agent’s prior beliefs, even in the case of quantum state preparation (emphasis original)”. The preparation device must be considered quantum mechanical also. The contribution of this paper uses the example of a certain (probability =1) experiment to present the following argument: If you posit that pre-existing properties fully determine the experimental outcome, this will violate the principle of locality (the authors make use of the Kochen-Specker theorem in the argument – the argument is presented in section 5). Therefore we cannot interpret a measurement as revealing an objective pre-assigned value. Certainty means certainty of the agent’s belief.
So, what’s the problem? No problem, just an observation of the limit to how helpful this in forming an ontological interpretation of QM (and, to be fair, the authors finish the paper by making clear they don’t claim this is the answer to all foundational questions). It seems precisely clear where the limit is. In the interpretation: “A probability is an agent’s degree of belief…” The agent and the agent’s degrees of belief are primitives in the implied ontology. There is no explanation or description of the agent, quantum mechanical or otherwise.
If quantum mechanics describes our world, we would like a generalized ontology which makes no distinction between an “agent” and any quantum system. I guess there are two ways to think of this: first, we could try to come to grips with a theory in which all quantum systems, even simple ones, are somehow agents which have beliefs. Offhand I don’t see how this can work. The second option (and my preference) is that we take the probabilities out of the subjective realm and put them (the quantum states) back into reality. The trick is that we have to do this in a way which respects the findings of the Bayesian analysis, meaning the quantum state can’t be considered fully objective. The solution would seem to be to consider the quantum state (between preparation and measurement) to be a propensity of the system under consideration which exists relative to the measuring system. You still have a dichotomy between facts (measurements/interactions) and probabilities (propensities), but both have their own form of existence. (Note my use of term “propensities” here is distinct from the usual Popperian sense which I gather does see them as objective).
Just like at the end of my previous post on this topic, I’ll note that the idea of generalizing the Bayesian approach to ubiquitously cover all quantum systems attracts me to a relational interpretation of QM. Matt Leifer had a good discussion of challenges facing the relational interpretation at Quantum Quandaries (here and here). Many of his points centered around the problem of how simple quantum systems could “choose” a consistent measurement basis. I’m interested to watch and see if these issues can be worked out. A paper was posted last year by Paul Merriam which takes an interesting approach to addressing some of these issues. I'll see if I can summarize it in a future post.
While I am persuaded that the Bayesian interpretation does win out over attempts to see quantum probabilities (or quantum states) as fully objective, there is a limit to how satisfying the analysis can be as an overall ontological interpretation of QM.
Here's a very brief summary. The authors note the fundamental category distinction in Bayesian probability theory between probabilities and facts. Probabilities cannot be reduced to facts; facts (the truth values of propositions) are used to update prior probability assignments.
In the context of a QM experimental setup, the quantum states are “catalogues of probabilities for measurement outcomes...” which “…summarize an agent’s degrees of belief about the potential outcomes of quantum measurements.” What might be less obvious is how to correctly interpret the preparation procedure. According to a common Copenhagen reading of the situation, the preparation procedure is described classically and the facts about the procedure determine the quantum state. (To reiterate, in the Bayesian interpretation probabilities can never be wholly determined by facts).
The authors set out to show that “the posterior state always depends on the agent’s prior beliefs, even in the case of quantum state preparation (emphasis original)”. The preparation device must be considered quantum mechanical also. The contribution of this paper uses the example of a certain (probability =1) experiment to present the following argument: If you posit that pre-existing properties fully determine the experimental outcome, this will violate the principle of locality (the authors make use of the Kochen-Specker theorem in the argument – the argument is presented in section 5). Therefore we cannot interpret a measurement as revealing an objective pre-assigned value. Certainty means certainty of the agent’s belief.
So, what’s the problem? No problem, just an observation of the limit to how helpful this in forming an ontological interpretation of QM (and, to be fair, the authors finish the paper by making clear they don’t claim this is the answer to all foundational questions). It seems precisely clear where the limit is. In the interpretation: “A probability is an agent’s degree of belief…” The agent and the agent’s degrees of belief are primitives in the implied ontology. There is no explanation or description of the agent, quantum mechanical or otherwise.
If quantum mechanics describes our world, we would like a generalized ontology which makes no distinction between an “agent” and any quantum system. I guess there are two ways to think of this: first, we could try to come to grips with a theory in which all quantum systems, even simple ones, are somehow agents which have beliefs. Offhand I don’t see how this can work. The second option (and my preference) is that we take the probabilities out of the subjective realm and put them (the quantum states) back into reality. The trick is that we have to do this in a way which respects the findings of the Bayesian analysis, meaning the quantum state can’t be considered fully objective. The solution would seem to be to consider the quantum state (between preparation and measurement) to be a propensity of the system under consideration which exists relative to the measuring system. You still have a dichotomy between facts (measurements/interactions) and probabilities (propensities), but both have their own form of existence. (Note my use of term “propensities” here is distinct from the usual Popperian sense which I gather does see them as objective).
Just like at the end of my previous post on this topic, I’ll note that the idea of generalizing the Bayesian approach to ubiquitously cover all quantum systems attracts me to a relational interpretation of QM. Matt Leifer had a good discussion of challenges facing the relational interpretation at Quantum Quandaries (here and here). Many of his points centered around the problem of how simple quantum systems could “choose” a consistent measurement basis. I’m interested to watch and see if these issues can be worked out. A paper was posted last year by Paul Merriam which takes an interesting approach to addressing some of these issues. I'll see if I can summarize it in a future post.
Tuesday, January 02, 2007
Making Abstract Truths Intelligible
The problem with abstract objects is that their existence seems required to provide truthmakers for our propositions about them. Nominalist and other deflationary accounts can’t adequately meet this requirement. Yet how could abstract objects be real if they aren’t part of our concrete world? In modern discussions, abstract objects are causally inert by definition. If they somehow exist in some platonic realm, how could we know them in the absence of any causal connection? (A previous post on abstract objects is here).
Well, we have been considering here a model of causality that incorporates abstract modal realism. The concrete world is a causal network of events which are actualized possibilities. The set of possibilities available to be actualized in an event is constrained by preceding or adjacent events but the outcome isn’t fully determined prior to a new actualization. Unactualized possibilities may be considered “abstract” in that they are non-concrete yet real, and abstract seems as good a term as any for this mode of being (see note on terminology at end of post).
So a certain kind of abstract entity does enter into causal connections. Specifically, the concrete events of the world make contact with abstract possible events. Then the question is can we use this theory to make sense of our seeming knowledge of abstract truths, such as the prototypical logical and mathematical ones?
Well, I don’t have a developed model of how our macroscopic brain/body system would accomplish this. But given the centrality of modality to our reasoning, and given an independently motivated theory that we, as natural systems, exist in a web of actualized possibilities, we can try to connect the dots. The idea would go something like this: we have a direct primitive acquaintance with possibility, which we leverage into knowledge of idealized abstract truths through a process of counterfactual analysis. It is this notion of “primitive” acquaintance which makes this process not just a matter of conceptual or psychological construction, but a matter of reaching toward metaphysical truths.
Terminological note: it is easy to get misled by terminology here and I have probably been sloppy at times. Often in discussions of modal realism (See SEP article on Actualism), a distinction is drawn between the “actual” and “mere” possibilia. Unless one subscribes to David Lewis’ model of modal realism, where possible worlds are all concrete and the term actual is an indexical, I suggest using actual and concrete interchangeably and ask the reader’s forbearance to not misread the fact that possibilities are “non-actual” as saying they don’t exist. They exist, but are non-concrete, hence abstract.
Well, we have been considering here a model of causality that incorporates abstract modal realism. The concrete world is a causal network of events which are actualized possibilities. The set of possibilities available to be actualized in an event is constrained by preceding or adjacent events but the outcome isn’t fully determined prior to a new actualization. Unactualized possibilities may be considered “abstract” in that they are non-concrete yet real, and abstract seems as good a term as any for this mode of being (see note on terminology at end of post).
So a certain kind of abstract entity does enter into causal connections. Specifically, the concrete events of the world make contact with abstract possible events. Then the question is can we use this theory to make sense of our seeming knowledge of abstract truths, such as the prototypical logical and mathematical ones?
Well, I don’t have a developed model of how our macroscopic brain/body system would accomplish this. But given the centrality of modality to our reasoning, and given an independently motivated theory that we, as natural systems, exist in a web of actualized possibilities, we can try to connect the dots. The idea would go something like this: we have a direct primitive acquaintance with possibility, which we leverage into knowledge of idealized abstract truths through a process of counterfactual analysis. It is this notion of “primitive” acquaintance which makes this process not just a matter of conceptual or psychological construction, but a matter of reaching toward metaphysical truths.
Terminological note: it is easy to get misled by terminology here and I have probably been sloppy at times. Often in discussions of modal realism (See SEP article on Actualism), a distinction is drawn between the “actual” and “mere” possibilia. Unless one subscribes to David Lewis’ model of modal realism, where possible worlds are all concrete and the term actual is an indexical, I suggest using actual and concrete interchangeably and ask the reader’s forbearance to not misread the fact that possibilities are “non-actual” as saying they don’t exist. They exist, but are non-concrete, hence abstract.
Tuesday, December 12, 2006
Gödel’s Platonism
I got around to reading Rebecca Goldstein’s brief and engaging book on Gödel -- Incompleteness: The Proof and Paradox of Kurt Gödel. The book centered on the irony that Gödel’s own philosophical interpretation of his work (which indeed may have driven his efforts to begin with) was in complete opposition to how it was most commonly interpreted by others.
Gödel was a Platonist, believing that the mind was able to make contact with absolute mathematical reality. Given that he was an attending member of the Vienna circle in the 1920’s, which was the locus of logical positivism, many assumed he was of like mind, believing there was no truth beyond what man could empirically discover. Gödel’s extreme reluctance to speak or write on his views helped make this misunderstanding possible. Indeed, the incompleteness theorems have often been co-opted by sloppy post-modernists (along with relativity theory and the uncertainty principle) in making the case for truth relativism. They would focus on the conclusion that we can’t construct formal systems (large enough to at least encompass arithmetic) that are both complete and provably consistent and treat this fact as revealing a limitation in our ability to reach absolute truth. Gödel believed the actual lesson was that the human mind can and does perceive truth beyond the capability of formal systems (equivalently, algorithmic computing machines).
[UPDATE 12 January 2012: For a review quite critical of Goldstein see Solomon Feferman's here. He says she has no basis for taking Godel's later platonism and suggesting it motivated his earlier seminal work.]
To digress a moment, I just about forgot I have an old post on Gödel. This blog is ably serving one of its functions -- an external memory module. In that post I noted the consensus of experts that while the incompleteness theorems may point toward philosophical conclusions (such as thinking the mind surpasses a computer), they don’t provide any proofs after you depart their formal setting. However, one philosophical stance I said they did appear to support was the notion of an ultimate limit on “objective” knowledge. (Note I also maintained that such an observation need not lead to thorough-going relativism.) Now, in reading more about Gödel’s own views, I’m not feeling confidant that assertion quite captures things.
In one of those happy coincidences, the recent update to the Online Papers in Philosophy blog maintained by Jonathan Ichikawa [UPDATE: this blog not longer exists] had a paper by eminent mathematical logician Solomon Feferman which examined one of Gödel’s rare talks (the 1951 “Gibbs” lecture). In the talk, Gödel presented the philosophical implications in terms of a disjunction thus: “Either…the human mind…infinitely surpasses the powers of any finite machine, or else there exist absolutely unsolvable Diophantine problems.” By the most reliable accounts, Gödel did indeed believe that the mind surpassed finite systems and therefore there were no (ideally) unsolvable problems, but he expressed a bit of caution in this talk by presenting the disjunction.
Feferman, in keeping with the usual deflationary mode of papers by experts on this topic, respectfully shows how the imprecision and complexity of these issues prevent one from reaching a logical proof of Gödel’s claim (or even ruling out that the disjuncts could both be true). Once again, the broad statements about the mind and its capabilities can’t be derived from the mathematical arguments which inspire them. Still, many interesting facets of these issues are illuminated in the discussion.
The Feferman paper included one (unpublished) Gödel quote which struck me as very insightful. Gödel (responding to something Turing had written) says: …”mind, in its use, is not static, but constantly developing, i.e., we understand abstract terms more and more precisely as we go on using them…though at each stage the number and precision of the abstract terms at our disposal may be finite, both…may converge toward infinity…” We are clearly finite and contingent creatures, and so the idea that we are in direct contact with Platonic truths is hard to support; but we do appear to have a gift of rationality which allows us to converge toward absolute truths. I see a connection here to the idea of modal rationalism, which I’ll explore in a future post.
One more note: that OPP update had another paper which touches on this topic, Philip Ebert’s “What Mathematical Knowledge could not be”. This is a nice survey of positions on the reality of mathematical objects; it doesn’t itself advance an argument.
Gödel was a Platonist, believing that the mind was able to make contact with absolute mathematical reality. Given that he was an attending member of the Vienna circle in the 1920’s, which was the locus of logical positivism, many assumed he was of like mind, believing there was no truth beyond what man could empirically discover. Gödel’s extreme reluctance to speak or write on his views helped make this misunderstanding possible. Indeed, the incompleteness theorems have often been co-opted by sloppy post-modernists (along with relativity theory and the uncertainty principle) in making the case for truth relativism. They would focus on the conclusion that we can’t construct formal systems (large enough to at least encompass arithmetic) that are both complete and provably consistent and treat this fact as revealing a limitation in our ability to reach absolute truth. Gödel believed the actual lesson was that the human mind can and does perceive truth beyond the capability of formal systems (equivalently, algorithmic computing machines).
[UPDATE 12 January 2012: For a review quite critical of Goldstein see Solomon Feferman's here. He says she has no basis for taking Godel's later platonism and suggesting it motivated his earlier seminal work.]
To digress a moment, I just about forgot I have an old post on Gödel. This blog is ably serving one of its functions -- an external memory module. In that post I noted the consensus of experts that while the incompleteness theorems may point toward philosophical conclusions (such as thinking the mind surpasses a computer), they don’t provide any proofs after you depart their formal setting. However, one philosophical stance I said they did appear to support was the notion of an ultimate limit on “objective” knowledge. (Note I also maintained that such an observation need not lead to thorough-going relativism.) Now, in reading more about Gödel’s own views, I’m not feeling confidant that assertion quite captures things.
In one of those happy coincidences, the recent update to the Online Papers in Philosophy blog maintained by Jonathan Ichikawa [UPDATE: this blog not longer exists] had a paper by eminent mathematical logician Solomon Feferman which examined one of Gödel’s rare talks (the 1951 “Gibbs” lecture). In the talk, Gödel presented the philosophical implications in terms of a disjunction thus: “Either…the human mind…infinitely surpasses the powers of any finite machine, or else there exist absolutely unsolvable Diophantine problems.” By the most reliable accounts, Gödel did indeed believe that the mind surpassed finite systems and therefore there were no (ideally) unsolvable problems, but he expressed a bit of caution in this talk by presenting the disjunction.
Feferman, in keeping with the usual deflationary mode of papers by experts on this topic, respectfully shows how the imprecision and complexity of these issues prevent one from reaching a logical proof of Gödel’s claim (or even ruling out that the disjuncts could both be true). Once again, the broad statements about the mind and its capabilities can’t be derived from the mathematical arguments which inspire them. Still, many interesting facets of these issues are illuminated in the discussion.
The Feferman paper included one (unpublished) Gödel quote which struck me as very insightful. Gödel (responding to something Turing had written) says: …”mind, in its use, is not static, but constantly developing, i.e., we understand abstract terms more and more precisely as we go on using them…though at each stage the number and precision of the abstract terms at our disposal may be finite, both…may converge toward infinity…” We are clearly finite and contingent creatures, and so the idea that we are in direct contact with Platonic truths is hard to support; but we do appear to have a gift of rationality which allows us to converge toward absolute truths. I see a connection here to the idea of modal rationalism, which I’ll explore in a future post.
One more note: that OPP update had another paper which touches on this topic, Philip Ebert’s “What Mathematical Knowledge could not be”. This is a nice survey of positions on the reality of mathematical objects; it doesn’t itself advance an argument.
Wednesday, November 29, 2006
Widening the Trail
Well, to follow up on the last post, I liked Strawson’s new paper a lot, but will take note that his “journey” took us to some places which seem pretty familiar.
His realism about experience led to a rejection of materialist monism, and thinking about how both experiential and non-experiential being can co-exist in any naturalistic way led him to consider panexperientialism (see Chalmers, 1996). He discussed the notion of inside and outside perspectives as a way to explain why reality may seem to have dual modes (Nagel 1974). He outlined the idea that the experiential could seen as the categorical basis of reality, while the non-experiential is the dispositional/relational dimension of reality investigated by physics (Russell 1927). At this point, trying to make further sense of these ideas took him outside the arena of philosophy of mind, strictly speaking, to a discussion about how the panexperientialist view relates to the topics of causality and the composition of individuals (see Rosenberg 2004, and, of course, Whitehead 1928).
I don’t mean this comment to be too critical: I think all this is a good thing. Strawson’s work, presented in his unique style, helps widen the trail and thus bolsters the case for these ideas.
[Updated 16 March 2009 for broken links]
His realism about experience led to a rejection of materialist monism, and thinking about how both experiential and non-experiential being can co-exist in any naturalistic way led him to consider panexperientialism (see Chalmers, 1996). He discussed the notion of inside and outside perspectives as a way to explain why reality may seem to have dual modes (Nagel 1974). He outlined the idea that the experiential could seen as the categorical basis of reality, while the non-experiential is the dispositional/relational dimension of reality investigated by physics (Russell 1927). At this point, trying to make further sense of these ideas took him outside the arena of philosophy of mind, strictly speaking, to a discussion about how the panexperientialist view relates to the topics of causality and the composition of individuals (see Rosenberg 2004, and, of course, Whitehead 1928).
I don’t mean this comment to be too critical: I think all this is a good thing. Strawson’s work, presented in his unique style, helps widen the trail and thus bolsters the case for these ideas.
[Updated 16 March 2009 for broken links]
Friday, November 24, 2006
Strawson Continues His Journey
[UPDATE 16 March 2009: the link to the paper mentioned below is unfortunately broken -- Strawson has a new home page, but it no longer has the link; the JCS special issue is also available on amazon.]
The recent JCS consisted of Galen Strawson’s recent paper “Realistic Monism: Why Physicalism Entails Panpsychism” as the target article, a number of critical responses from other philosophers, and finally Strawson’s reply. Recall that this was the paper which argued that realism about experience, and a rejection of brute emergence of experience from non-experiential parts, leads to panexperientialism. Except that instead of simply replying to his critics, Strawson offered extended further arguments and speculations on the problem of experience in its full metaphysical dimension with, as a bonus, a lengthy digression on Descartes (arguing that the usual “substance dualist” label is something of a caricature – in various writings/correspondence he expressed a desire to avoid distinguishing substance from its attributes).
I thought the whole thing was a marvelous read and a great contribution: seemingly eccentric yet an honest and insightful inquiry. It is good to see him bring more attention to the arguments for panexperientialism.
I’m not going to try to do justice to the whole thing (nearly 100 pages!), but let me discuss some highlights. (Unfortunately, it is not online at this time that I can see).
The distillation of the problem is that he (and many of us) want to affirm that experiential and non-experiential truths are fundamental, and cannot be reduced to the other -- yet at the same time we would like to have a monism.
Strawson offers this definition of “Equal-Status Fundamental Duality monism” (ESFD monism for short):
The question is how reality can be fundamentally dual yet single. How can we develop such a view?
Before going on, I should mention a subsidiary thesis in Strawson’s thinking which was brought out in one of the commentaries, that is, a commitment to “smallism”: “All facts are (fully) determined by ultimates.” In other words, our tendency to view reductive explanations as good explanations is endorsed: the question is what sort of ultimate or ultimates can support reality (a post on this topic is here).
Also, to the extent that experience is determined to be an ultimate, Strawson doesn’t think that a separate subject of experience is required at the fundamental level (see Justin’s post at his Panexperientialism blog for more on this).
But, acknowledging the tension and possible incoherence in combining a duality and a monism in the above definition, Strawson next steps back to consider what happens if we give up on the fundamental duality. He asserts that if either experiential or non-experiential being has to “give way”, it cannot be the experiential which does so, given that it is what we know directly, at least in certain respects (Strawson also discusses the epistemology of this direct acquaintance later in the paper). If, for the purposes of our analysis, we let the non-experiential give way, we are left with the notion that the “energy-stuff that makes up the whole of reality is itself is something that is experiential in every respect. The universe consists of experience…arrayed in a certain way”. To be clear, we’re not talking about passive experiential content of some sort to be perceived by somebody, it is that the active energy of nature is intrinsically experiential. Strawson calls this position “pure panpsychism”.
(Terminological note: for Strawson there is no technical reason to distinguish between “panpsychism” and “panexperientialism” given his view that at the micro-level, there is no distinction between experience and a subject of experience. I think panexperientialism is to be preferred for clarity: no one is attributing human-style minds to more fundamental units of nature.)
So the 3 options are radical eliminativism about experience, ESFD monism, or pure panpsychism. The first is a non-starter, while the second is appealing but probably incoherent as stated. Can we make pure panpsychism work?
Strawson next considers challenges facing this notion of experience as the active energy of nature. He ponders that space must supervene on this ultimate energy/activity, rather than being a container for it. Causality and the laws of nature must also arise from this working of this ultimate experiential activity as well. The biggest challenge, though, is what is often called the combination problem, but which Strawson calls the composition problem.
The composition problem, dating to William James, is how the macro-level experience we’re acquainted with could be built from micro-level experiences.
Now, some commentaries on the target paper think that the composition problem argues decisively against panpsychism. One criticism of this type argues that Strawson’s assumptions about our epistemological acquaintance with experience implies we would be “privy to” the micro-level experiences themselves, and this is not the case. Strawson denies the need for any commitment to such a “full revelation” epistemology. We only are acquainted with some aspects of experience (partial revelation). (For a description of another critique based on the composition problem and a counter-argument, I refer you to another fine post at the Panexperientialism blog.)
Toward the end of the paper, Strawson puts forth some speculative thoughts on the composition problem and how things must be if panpsychism really describes nature. He ponders the fact that our acquaintance with experience is “from the inside”. It must also then, have an “outside”. This leads to a glimmer of how a kind of ESFD monism could be true, if the inside and outside are both essentially aspects of the being of an experience. But this “outside” can’t be something ontologically distinct from the experience.
His musings turn next to issues of causation and composition. We might say the outside of an experience is its relation with other experiences, including its relation to experiences which compose it, or of which it is a part. Key to thinking about how to characterize these ideas is to stress the active rather than passive nature of experience. Rather than an atom of experience as a fundamental unit, we might speak of an “experiencing”.
He says there would be a first-person ontology intrinsic to an experiencing, but experiencings must exist in a fashion which gives rise to what we think of as third-person phenomena. These two “perspectival” realities coexist with the monistic reality that all is experience.
With regard to the composition problem, it must work something like this: “…experiencings… can be as they are to themselves…compatibly with their having causal effects on other [experiencings] and compatibly with their part in constituting other…distinct [experiencings].” And given the “Laws of Experiential Nature, whatever they are,” when one constitutes part of another the second will not have access to the inside nature of the first in the same way the first does.
To summarize:
He says while these thoughts are speculative, it is not uncontrolled speculation, more importantly it is not unwarranted. A commitment to the reality of experiential being, combined with a subsidiary commitment to “smallism”, leads directly to this kind of account.
Given the length of this post, I will offer some additional comments of my own in a follow up.
The recent JCS consisted of Galen Strawson’s recent paper “Realistic Monism: Why Physicalism Entails Panpsychism” as the target article, a number of critical responses from other philosophers, and finally Strawson’s reply. Recall that this was the paper which argued that realism about experience, and a rejection of brute emergence of experience from non-experiential parts, leads to panexperientialism. Except that instead of simply replying to his critics, Strawson offered extended further arguments and speculations on the problem of experience in its full metaphysical dimension with, as a bonus, a lengthy digression on Descartes (arguing that the usual “substance dualist” label is something of a caricature – in various writings/correspondence he expressed a desire to avoid distinguishing substance from its attributes).
I thought the whole thing was a marvelous read and a great contribution: seemingly eccentric yet an honest and insightful inquiry. It is good to see him bring more attention to the arguments for panexperientialism.
I’m not going to try to do justice to the whole thing (nearly 100 pages!), but let me discuss some highlights. (Unfortunately, it is not online at this time that I can see).
The distillation of the problem is that he (and many of us) want to affirm that experiential and non-experiential truths are fundamental, and cannot be reduced to the other -- yet at the same time we would like to have a monism.
Strawson offers this definition of “Equal-Status Fundamental Duality monism” (ESFD monism for short):
Reality is substantially single. All reality is experiential and all reality is non-experiential. Experiential and non-experiential being exist in such a way that neither can be said to be based in or realized by or in any way asymmetrically dependent on the other (etc.)
The question is how reality can be fundamentally dual yet single. How can we develop such a view?
Before going on, I should mention a subsidiary thesis in Strawson’s thinking which was brought out in one of the commentaries, that is, a commitment to “smallism”: “All facts are (fully) determined by ultimates.” In other words, our tendency to view reductive explanations as good explanations is endorsed: the question is what sort of ultimate or ultimates can support reality (a post on this topic is here).
Also, to the extent that experience is determined to be an ultimate, Strawson doesn’t think that a separate subject of experience is required at the fundamental level (see Justin’s post at his Panexperientialism blog for more on this).
But, acknowledging the tension and possible incoherence in combining a duality and a monism in the above definition, Strawson next steps back to consider what happens if we give up on the fundamental duality. He asserts that if either experiential or non-experiential being has to “give way”, it cannot be the experiential which does so, given that it is what we know directly, at least in certain respects (Strawson also discusses the epistemology of this direct acquaintance later in the paper). If, for the purposes of our analysis, we let the non-experiential give way, we are left with the notion that the “energy-stuff that makes up the whole of reality is itself is something that is experiential in every respect. The universe consists of experience…arrayed in a certain way”. To be clear, we’re not talking about passive experiential content of some sort to be perceived by somebody, it is that the active energy of nature is intrinsically experiential. Strawson calls this position “pure panpsychism”.
(Terminological note: for Strawson there is no technical reason to distinguish between “panpsychism” and “panexperientialism” given his view that at the micro-level, there is no distinction between experience and a subject of experience. I think panexperientialism is to be preferred for clarity: no one is attributing human-style minds to more fundamental units of nature.)
So the 3 options are radical eliminativism about experience, ESFD monism, or pure panpsychism. The first is a non-starter, while the second is appealing but probably incoherent as stated. Can we make pure panpsychism work?
Strawson next considers challenges facing this notion of experience as the active energy of nature. He ponders that space must supervene on this ultimate energy/activity, rather than being a container for it. Causality and the laws of nature must also arise from this working of this ultimate experiential activity as well. The biggest challenge, though, is what is often called the combination problem, but which Strawson calls the composition problem.
The composition problem, dating to William James, is how the macro-level experience we’re acquainted with could be built from micro-level experiences.
Now, some commentaries on the target paper think that the composition problem argues decisively against panpsychism. One criticism of this type argues that Strawson’s assumptions about our epistemological acquaintance with experience implies we would be “privy to” the micro-level experiences themselves, and this is not the case. Strawson denies the need for any commitment to such a “full revelation” epistemology. We only are acquainted with some aspects of experience (partial revelation). (For a description of another critique based on the composition problem and a counter-argument, I refer you to another fine post at the Panexperientialism blog.)
Toward the end of the paper, Strawson puts forth some speculative thoughts on the composition problem and how things must be if panpsychism really describes nature. He ponders the fact that our acquaintance with experience is “from the inside”. It must also then, have an “outside”. This leads to a glimmer of how a kind of ESFD monism could be true, if the inside and outside are both essentially aspects of the being of an experience. But this “outside” can’t be something ontologically distinct from the experience.
His musings turn next to issues of causation and composition. We might say the outside of an experience is its relation with other experiences, including its relation to experiences which compose it, or of which it is a part. Key to thinking about how to characterize these ideas is to stress the active rather than passive nature of experience. Rather than an atom of experience as a fundamental unit, we might speak of an “experiencing”.
He says there would be a first-person ontology intrinsic to an experiencing, but experiencings must exist in a fashion which gives rise to what we think of as third-person phenomena. These two “perspectival” realities coexist with the monistic reality that all is experience.
With regard to the composition problem, it must work something like this: “…experiencings… can be as they are to themselves…compatibly with their having causal effects on other [experiencings] and compatibly with their part in constituting other…distinct [experiencings].” And given the “Laws of Experiential Nature, whatever they are,” when one constitutes part of another the second will not have access to the inside nature of the first in the same way the first does.
To summarize:
Experiential realities may be said to function as non-experiential but experience-causing realities for other experiential realities, and to function as non-experiential but experience-constituting realities for other experiential realities. Again, it may be said that although there is no non-experiential being absolutely speaking, there is non-experiential being relatively or relationally speaking.[Emphasis original]
He says while these thoughts are speculative, it is not uncontrolled speculation, more importantly it is not unwarranted. A commitment to the reality of experiential being, combined with a subsidiary commitment to “smallism”, leads directly to this kind of account.
Given the length of this post, I will offer some additional comments of my own in a follow up.
Friday, November 17, 2006
Modal Realism and the Cosmological Argument
It seems to follow from a certain kind of realism about metaphysical possibilities that a version of the cosmological argument goes through. The idea is that if the space of possibilities exists, then it exists necessarily. The actualized concrete events of the world are contingent and depend on the necessary space of possibilities.
There are many variations, but the cosmological argument states that the chain of events needs a necessary first cause to get started. Or else it is cast in terms of arguing that contingent things ultimately must depend on a necessary self-existent thing. In the model under consideration here contingent things (events) are actualizations of possibilities. A given event is subject to causal constraint by prior or adjacent events but is always also dependent on the space of possibilities.
There seems to be no well motivated reason to consider an objection involving, say, an infinite chain of meta-modal spaces upon which the first-order space of possibilities depends. So, the space of possibilities would be a self-existent necessary entity and the argument goes through.
[UPDATE: 5 February 2009 -- This modal realism-inspired cosmological argument should not be confused with other arguments which goes by the name "modal". These arguments (which doesn't work IMO) try to use modal logic to imply theism: see discussion here for instance.]
There are many variations, but the cosmological argument states that the chain of events needs a necessary first cause to get started. Or else it is cast in terms of arguing that contingent things ultimately must depend on a necessary self-existent thing. In the model under consideration here contingent things (events) are actualizations of possibilities. A given event is subject to causal constraint by prior or adjacent events but is always also dependent on the space of possibilities.
There seems to be no well motivated reason to consider an objection involving, say, an infinite chain of meta-modal spaces upon which the first-order space of possibilities depends. So, the space of possibilities would be a self-existent necessary entity and the argument goes through.
[UPDATE: 5 February 2009 -- This modal realism-inspired cosmological argument should not be confused with other arguments which goes by the name "modal". These arguments (which doesn't work IMO) try to use modal logic to imply theism: see discussion here for instance.]
Friday, November 10, 2006
Modal Realism, Modal Rationalism
The case for modal realism can be motivated in a few ways. It often begins with contemplating the everyday modal propositions we make about the world. We seem to know that things might have been different, after all, and there are different ways the world could be in the future. Some dinosaurs might have survived the meteor catastrophe. I might have tried to avoid traffic by leaving earlier this morning. It’s possible that I might stop writing this post now, and finish it later. By virtue of what can these propositions be considered true or false? Being of realist persuasion, I think there must be something in the reality outside our minds to provide truthmakers for these propositions (my prior posts on modality and modal realism can be found here).
Modal realism also seems linked to realism about causality, when the causal connection is seen as a counterfactual dependence. I might not have checked my e-mail: if I hadn’t, I would not have seen your message.
In a deflationary metaphysics where there exists one world subject to deterministic laws, all connections are necessary. Possibility and contingency would only be illusions. They would only exist in our minds. (Likewise it seems to me that the directional flow of time and causality would have no parallel in the world; necessary connections are symmetric.)
But given a naturalistic worldview, our minds arise from the same stuff as the rest of the world. Is it plausible that a world which lacks real possibility would give rise to creatures for whom the notion is indispensable?
Of course, we know strict determinism is false, given the real indeterminism present in quantum mechanics. I have argued elsewhere for an interpretation which sees the quantum states as incorporating real (although not concrete) possibilities, while measurements are concrete actualization events.
Leaving aside for now the tough problem of describing the modal space in any detail (see note below), I am intrigued by the notion that the modal propositions and modal reasoning we employ are grounded in a modal reality.
The thesis of modal rationalism, as explored by David Chalmers in section 10 of this paper, is the idea that our notion of what is conceivable (logically possible) does indeed match what is metaphysically possible. He examines and argues against proposals that these need be distinct modal spaces.
If I couple modal rationalism with a modal realism which posits that metaphysical possibilities really exist (outside the cranium), this creates what I think is a fascinating picture. We, along with all natural phenomena, are continually actualized from a space of possibilities: our roots in this space form the basis of our evolved faculty for modal reasoning.
Note: For a great discussion of how to flesh out the space of metaphysical possibility, and related issues including modal rationalism, I recommend Richard Chappell’s recent draft paper. [UPDATE 25 January 2010: here's a link to a pdf of the final paper from Chappell's website.]
Modal realism also seems linked to realism about causality, when the causal connection is seen as a counterfactual dependence. I might not have checked my e-mail: if I hadn’t, I would not have seen your message.
In a deflationary metaphysics where there exists one world subject to deterministic laws, all connections are necessary. Possibility and contingency would only be illusions. They would only exist in our minds. (Likewise it seems to me that the directional flow of time and causality would have no parallel in the world; necessary connections are symmetric.)
But given a naturalistic worldview, our minds arise from the same stuff as the rest of the world. Is it plausible that a world which lacks real possibility would give rise to creatures for whom the notion is indispensable?
Of course, we know strict determinism is false, given the real indeterminism present in quantum mechanics. I have argued elsewhere for an interpretation which sees the quantum states as incorporating real (although not concrete) possibilities, while measurements are concrete actualization events.
Leaving aside for now the tough problem of describing the modal space in any detail (see note below), I am intrigued by the notion that the modal propositions and modal reasoning we employ are grounded in a modal reality.
The thesis of modal rationalism, as explored by David Chalmers in section 10 of this paper, is the idea that our notion of what is conceivable (logically possible) does indeed match what is metaphysically possible. He examines and argues against proposals that these need be distinct modal spaces.
If I couple modal rationalism with a modal realism which posits that metaphysical possibilities really exist (outside the cranium), this creates what I think is a fascinating picture. We, along with all natural phenomena, are continually actualized from a space of possibilities: our roots in this space form the basis of our evolved faculty for modal reasoning.
Note: For a great discussion of how to flesh out the space of metaphysical possibility, and related issues including modal rationalism, I recommend Richard Chappell’s recent draft paper. [UPDATE 25 January 2010: here's a link to a pdf of the final paper from Chappell's website.]
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