6/29/12

Putnam, Hilary - A Philosopher Looks at Quantum Mechanics (Again)

06/29/2012

Philosophy in an Age of Science, Harvard University Press, 2012

Author revisits the paper, "A Philosopher Looks at Quantum Mechanics", released before Bell's "famous" paper on the Einstein-Podolski-Rosen paradox. This was an occasion to flesh out the paradox that if non-locality in quantum mechanics  was correct, Einsteinian special relativity is refuted (pg 127). Author then produces an extensive quote from his previous (1965) paper, where the "operationalist" theory of scientific method and theory is assumed to be false and his theory of scientific realism is proposed (pg128-131). Author sees a problem with the proposed version of scientific realism and quantum mechanics, and next goes on to describe what quantum mechanics posits, and the problems it raises. pg 131-3 [Summarizing author's summary of quantum physics is a misguided affair.]

The first problem considered is Schrodinger's cat, where a macro-level object (a cat) is in a superposition based on a quantum "state" (dead/alive). In effect, the probability of death/life is 50/50, but the cat is in a "superposition" based on the un-collapsed quantum state. At least, this is the interpretation given by Von Neumann, discussed next by author. With Von Neumann, the cat collapses into one particular physical state when it is "observed" (pg133-4). Author considers other interpretations to the quantum problems, including Bohm and Ghirardi-Rimini-Weber (GRW). (pg 134-5). For Bohm, particles have definite positions and momenta, but because of a "hidden-variable" that is from some sort of "velocity field". (pg135-6) The GRW theory posits that each particle has a tiny probability of collapsing, thus with macroscopic objects collapse is all but certain. (pg136-7)

Author recounts his meeting with Einstein, who said that he didn't really believe the Von Neumann "collapse" assumption (pg137), and then reviews the theory of quantum mechanics he found most plausible in his earlier paper. Author believed that there was a distinction between micro- and macro-observables, that macro- had definite positions and values at all times, but micro- did not, and that was a relationship between macro- measurement and micro-observables (pg138). Author then moves to a chart that maps four possible interpretations of QM, that is based primarily on whether there is collapse or not (pg139). Author then describes (reviews) the views in the table (pg140-1), and then argues for which theories he thinks we should discard (pg141-143).

Author has moved from the Von Neumann theory that macro-objects don't have superposition and therefore when they interact with micro-objects that do, they cause collapse (in other words, collapse is external to the system), to the idea of spontaneous collapse (like GRW). However, author does not fully support GRW because each particle may violate the law of conservation of energy (pg142). Author gives a thought experiment to make the multiple worlds/no collapse theory seem implausible (pg143-4), by showing that the probability of one outcome in a Schrodinger's cat-like experiment will be irrelevant because the actual worlds will roughly be 50/50 (dead/alive). Thus either a GRW-esque theory of collapse or a Bohm-esque theory of hidden variables are what we are left with. The next difficulty, as well, is that for either of these interpretations to work, "absolute time" must also be included (pg145-6). Author suggests the possibility that space-time is literally super-imposed onto itself, like two discrete space-times, both of which are internally Einsteinian, and then "background time" is only necessary when they are combined.


 

6/22/12

Putnam, Hilary - The Content and Appeal of "Naturalism"

06/22/2012

Philosophy in an Age of Science, Harvard University Press, 2012

Author complains that "naturalism" is often undefined but ascribed to, and one place it is defined, in Boyd, Gasper, & Trout's Philosophy of Science glossary, is a disjunctive definition, comprised of two possibilities:
1. all phenomena are subject to natural laws
2. the methods of natural science is applicable in every area of inquiry

Author considers both using an example of a phenomenon of a usually clear writer composing a paragraph that is difficult to interpret. (pg 110-111) In the first case, the definition is trivial or absurd, and in the second it seems risible to claim that interpretation has a scientific approach like physics does, author argues. To really understand naturalism, author argues, one must inspect the alternative; it isn't "supernaturalism" or "occult", but "conceptual pluralism". Author's conceptual pluralism involves the "insistence that various sorts of statements" are as fully valid and true as the statements of empirical science. (pg112)

Author starts with the instability of the naturalist approach; that it can slip into Richard Rorty's anti-naturalism or a kind of Lewisonian Aristotelianism. Author talks about a common move in naturalism: to take a "minimalist" perspective toward one's ontology, in that anything that is real can be reduced to a description in "first grade" conceptual systems. The problem is (as usual) intentional conceptual schemes, where meaning, reference, beliefs and so on enter. Quine famously denied these were real things, most notably (according to author) by attacking reference (pg115). Quine argued that "x verbs y" is equivalent to "(cosmos minus x) verbs (cosmos minus y)." Because of the indeterminacy of reference, it does not pick anything out. (Using causation rather than correspondence is no help-pg116) Thus language is an internal system that does not extensionally connect to the world (pg116), which author points out looks a lot like Rorty's anti-realist picture. So minimalist naturalism may collapse into Rortian anti-realism. (pg117) Author pauses briefly to give a preview of his alternative picture (pg118). Author points out an alternative picture of reference, given by Lewis, in which there are "objective similarities" between objects/properties/classes. Author argues that in order to capture predicates like "is a chair", you need to add sortal elements like "affords sitting" rather than just color, shape, mass, etc. Thus there may be objective intentional objects, which author declares to be highly medieval/Aristotelian. (pg118-9)

The next (final) discussion is about the appeal of naturalism, and author discusses two arguments:
1. Argument from composition/evolution: the origin of the universe was fields and particles, until evolution, which is composed of fields and particles. (pg119-120)
2. If you can't reduce everything, something is "unexplained" (pg120)
Author spends the most time refuting 1 by first attacking how using 'mereological sums' to reduce objects will miss the similarities between objects that are slightly composed differently, and will miss modal discussions, since there is no "me" that ate a different dinner last night-- that would be a different person. (pg 120-123)
To deal with argument 2, this is simply something not to be afraid of. Author talks about how philosophers admit that an empirical inquiry like geology is legitimate but has yet to be reduced to physics, but nevertheless has acceptable terms like "true/false" "refer", etc. (pg124)


6/15/12

Putnam, Hilary - From Quantum Mechanics to Ethics and Back Again

06/15/2012

Philosophy in an Age of Science, Harvard University Press 2012

This chapter is first autobiographical about author's interests in ethics throughout author's career. Author continues to believe that ethics is a legitimate realm of knowledge, as author wrote in 1974. But the autobiographical remarks go on to consider how author is misunderstood to be leaving behind scientific realism for "common sense realism". This kicks off an examination of the term "scientific realism". The first discussion of "internal realism", which Putnam is accused of being in his mid-career, came in 1976 under the "Realism and Reason" address to the APA (Eastern). But really author prefers to have used "scientific realism" rather than "internal" in his opening remarks back then. By the end of the 1976 paper, author had formulated a new theory called "internal realism", which was different from the quick reference author made at the outset. This led to much confusion, particularly evident in De Gaynesford's book. What this confusion brought out was a deeper understanding of the limit of scientific realism, or of internal realism, in that author advanced it as another empirical theory, but as such the anti-realist must reject at least one empirical theory. This, according to author, begs the question against anti-realism, or at least should allow one to be both an anti-realist for language but a scientific realist for empiricism (pg56).

Author attempts to show how conceptual relativity may be compatible with realism in metaphysics (pg56). The idea is that cognitive equivalence of theories and preservation of explanations do not need to preserve "ontology", or the real objects that are supposed by the theory. Author also talks about not needing mereological sums or all the particular axioms that mereology may entail, and the question about whether sums /really/ exist as a pseudo-question. (pg57-8) 

The next discussion is about why author gave up functionalism: two reasons: (1) it wouldn't allow for reference to objects in the world, it didn't allow for "world-involving abilities" and (2) not only are mental states compositionally plastic, but also computationally plastic [this somehow is a refutation...]. (pg59) With reference being a relation between people and actual objects, it is possible to avoid the layer of sensations that were part of Cartesian dualism (pg60-1).

The point of this discussion was to return to rejecting one form of metaphysical realism (that there is precisely one way to describe the world), and also still allow for other forms, compatible with conceptual relativity. Author then describes how that is possible (pg63-4): allow for independent descriptions of the same one world. This is different, according to author, from conceptual pluralism (pg64) which has non-translatable forms of the world (levels). Within the field of science, physics perhaps the most salient case, there are translatable but also separate interpretations of the physical world.

Author then turns to a few objections and sore spots his view might touch. The first is the Wittgensteinian sense that thinking about realism and anti-realism is just thinking about nonsense. Author rejects that out of hand. The second is that talk of "states of affairs" ("aspects of reality") is unclear and imprecise; this is a sort of Quinean/Davidsonian objection (pg66-7). Quine eschewed in ontology anything without precise identity and non-identity conditions, and with things like states of affairs (and many intentional states), they were not precise enough and thus were discarded in science. Author answers by claiming that the term "states of affairs" is a 'broad-spectrum notion' that is a paraphrase of more precise understandings of objects. Davidson's purpose is to remain far away from even the specter of the correspondence theory of truth. Author: use a disquotational theory of truth where nothing is added by asserting the truth of a proposition (pg68).

Author closes by considering himself in the pragmatist tradition, and specifically admiring two beliefs from them: (1) language is not just description and evaluation, two categories which must never touch. (2) Philosophy should matter to our "moral and spiritual lives". (pg71) Interestingly author says that it is a "pipe dream" that philosophy will become a "cumulative body of knowledge". 


6/1/12

Gilmore, James - The Good and the Good of the Soul

06/01/2012

(Unpublished)

Author discusses how just action relates to the soul, and how knowledge relates to the soul, in Plato's Socratic dialogues. There are three ways it seems knowledge is related to the soul:
1) Wisdom is a virtue, characteristic of excellence of the soul
2) Knowledge of justice and avoiding injustice will mean you will know what to do (and what to avoid), thus putting your soul aright
3) Knowledge is pleasurable

The classic interpretation is that knowledge in general, and knowledge of justice, contribute to "psychic welfare", or the goodness of one's soul. Thus "the good is one's own good". The difficulty lies in "framing" the relationship between justice and the good of the soul. Author continues to talk about problems with this the classic interpretation.

The first discussion is sparked by Sachs, who points out that the well-ordered soul has intelligence, courage, and self-control, though none of these qualities are particularly just, e.g. could be also held by an evildoer, or someone who commits injustice. Further, Sachs raises the issue of whether anything in particular is required of the just man, or if it is to simply avoid injustice. Author argues that Plato does give prescriptive actions to the just philosopher, namely the burden of ruling.

Author uses Irwin's notation for two kinds of justice, one that is just for the city, or c-justice (encompassing just actions, just behavior), and the other kind will be personal orderliness, psychic welfare, or p-justice. With these two kinds in place, Plato needs to prove that a c-just person is also p-just, and also that a p-just person will be c-just. Sachs argues that Plato does not show the connections. There is a problem between the 'thin' account of p-justice and the need for a richer account of the permissible and required acts of c-justice.

Author tries to diagnose the problem: things that are good-for-me (p-just) don't seem to be good-in-general, or c-just. However, author instead argues that things are only good-for-me if they are indeed good-in-general. This may dispel some confusion around the apparent hedonistic view Socrates dons in Republic Book 9. Instead, author takes the Philebus to be Plato's settled view on pleasure, in that it is a 'value-tracker' or pleasure is the upshot of good "processes". Second, author argues that Plato needs to talk about pleasure as a good-in-itself in the Republic since that is what Socrates' interlocutors assumed it is. The biggest advantage the c-unjust man has is pleasure, so Plato needs to argue that the c-unjust man has less pleasure than the c-just, though this leaves it open whether pleasure really is a good-in-itself.

Author moves to his discussion, first of "psychic harmony". For Plato, the human good is being a certain kind of person, the one with a well-ordered soul, or with knowledge of justice. There is a functional account of what psychic harmony is in Republic Books 5-7, and then Book 9 tells why PH is good. The functional account of PH is that reason instructs all other parts of the soul by its access to truth about "what is best". But that still leaves the content of goodness, or justice, undiscovered. Author claims it can't be that the good is just the ordering of the soul, since then the good = ordering the soul, and ordering the soul = the good. Author claims this is uninformative and does not say why goodness is worthwhile. The problem here is that not only does c-justice seem under-defined, so does p-justice.

Author continues by exploring Plato's other thoughts in the Republic Book 4 about the human good. Perhaps it's reason managing all the different desires of all the different parts, in some sort of optimal or maximal way. But this doesn't seem right since reason's desires get preferential treatment. It may be that Plato wants there to be two elements: all desire satisfaction (for all parts of the soul), and also the intrinsic value of rational agency, or of the rule of reason. But even if this is the p-justice, the only relevant part for c-justice is reason; and Plato even suggests that other desires are weighted hardly at all even for p-justice. Author reviews the arguments in Republic Book 9 for p-justice, and the value of it and compares them to the Philebus. Importantly, author points out that Plato doesn't want to consider three pleasurable things: wisdom, honor, and money. Instead, these are three kinds of pleasure, each providing its own kind of pleasure. But then a problem arises in attempts to compare these three kinds. The first argument is that the philosopher has experienced all the kinds, and therefore can judge. The second argument is that each kind of pleasure has "intrinsic features" that make them more or less "true" or 'legitimate'. The argument here is that wisdom is stronger than honor or money since wisdom partakes in something eternal, while honor or money are changeable and 'mortal'. 

Author discusses pleasure as a process, a 'filling-up' (greek: plerosis) rather than a state. Knowledge, then, would not technically be pleasurable, though learning would be. Author circles back to what is doing the filling, e.g.: wisdom (which is more eternal and truer), or food (mortal, changeable). What is more the issue, rather than the process/state distinction, is the nature of the lack, and what it needs to fulfill it. Instead of having desires fulfilled being good, it's that getting what you're missing is the good, and it is better to get wisdom than food, since wisdom is satisfying permanently, and food is only temporarily satisfying. This interpretation also has the advantage of 'ecology', being that our soul naturally lacks certain things but pursues them according to those lacks-- food being lower than wisdom, but both are constitutive lacks of the human being.

Author circles back to pleasure being either the value-maker or the value-tracker. The favored interpretation from the author is pleasure is the value-tracker. Pleasure is identified with a process, which is a becoming, not a being, and thus not a good-in-itself. [Interestingly, it is Millgram who equates conviction in belief with pleasure in an end or activity.]