Online research in philosophy

The way a rational agent changes her belief in certain propositions/hypotheses in the light of new evidence lies at the heart of Bayesian inference. The basic natural assumption, as summarized in van Fraassen's Reflection Principle ([1984]), would be that in the absence of new evidence the belief should not change. Yet, there are examples that are claimed to violate this assumption. The apparent paradox presented by such examples, if not settled, would demonstrate the inconsistency and/or incompleteness of the Bayesian approach, (...) and without eliminating this inconsistency, the approach cannot be regarded as scientific. The Sleeping Beauty Problem is just such an example. The existing attempts to solve the problem fall into three <span class='Hi'>categories</span>. The first two share the view that new evidence is absent, but differ about the conclusion of whether Sleeping Beauty should change her belief or not, and why. The third category is characterized by the view that, after all, new evidence (although hidden from the initial view) is involved. My solution is radically different and does not fall into either of these <span class='Hi'>categories</span>. I deflate the paradox by arguing that the two different degrees of belief presented in the Sleeping Beauty Problem are in fact beliefs in two different propositions, i.e., there is no need to explain the (un)change of belief. The Sleeping Beauty Problem The Problem Deflated 2.1 From contradiction to consistency 2.2 The inanimate version 2.3 Back to SB Summary CiteULike Connotea Del.icio.us What's this? (shrink)

Karl Popper famously opposed Marxism in general and its philosophical core – the Marxist dialectic – in particular. As a progressive thinker, Popper saw in dialectic a source of dogmatism damaging to philosophy and political theory. Popper had summarized his views on dialectic in an article that was first delivered in 1937 and subsequently republished as a chapter of his book (2002, pp. 419-451), where he accuses Marxist dialecticians of not tolerating criticism. Ironically, Popper’s view that all Marxist dialecticians dogmatically (...) dismiss any criticism of dialectic by claiming that their opponents do not understand dialectic makes his position no less dogmatic. Indeed, any attempt to criticise Popper’s views on dialectics would be seen only as an additional example of responses by “dogmatic dialecticians”, making his theory essentially immune. This completely prevents dialecticians from being able to criticise Popper’s views. This is exactly the opposite of what the great philosopher wanted. Therefore, for the sake of “anti-dogmatic science” it is desirable and even necessary to defend dialectic. In this work I address several central points about Popper’s criticism of Marxist (materialist) dialectic. In particular, I (a) analyse Popper’s definition of dialectic as the dialectic triad (thesis, anti-thesis, synthesis) and contrast it with a notion of dialectic as a much more complex concept which occurs in dialectical materialism today, where the triad represents only one of the aspects; (b) compare dialectic with the trial and error method; (c) discuss the place of dialectic amongst valid scientific methods: Does dialectic accept logical contradictions; (e) discuss lessons dialecticians should learn from Popper’s criticism. I will test my arguments as to their constructiveness and will demonstrate explicitly the nature of my disagreement with Popper - thereby trying to avoid the “dogmatic dialecticians” response as much as possible. (shrink)

There has recently been a good deal of controversy about Landauer's Principle, which is often stated as follows: The erasure of one bit of information in a computational device is necessarily accompanied by a generation of kTln2 heat. This is often generalised to the claim that any logically irreversible operation cannot be implemented in a thermodynamically reversible way. John Norton (2005) and Owen Maroney (2005) both argue that Landauer's Principle has not been shown to hold in general, and Maroney offers (...) a method that he claims instantiates the operation Reset in a thermodynamically reversible way. In this paper we defend the qualitative form of Landauer's Principle, and clarify its quantitative consequences (assuming the second law of thermodynamics). We analyse in detail what it means for a physical system to implement a logical transformation L, and we make this precise by defining the notion of an L-machine. Then we show that logical irreversibility of L implies thermodynamic irreversibility of every corresponding L-machine. We do this in two ways. First, by assuming the phenomenological validity of the Kelvin statement of the second law, and second, by using information-theoretic reasoning. We illustrate our results with the example of the logical transformation 'Reset', and thereby recover the quantitative form of Landauer's Principle. (shrink)

There has recently been a good deal of controversy about Landauer's Principle, which is often stated as follows: The erasure of one bit of information in a computational device is necessarily accompanied by a generation of kT ln 2 heat. This is often generalised to the claim that any logically irreversible operation cannot be implemented in a thermodynamically reversible way. John Norton (2005) and Owen Maroney (2005) both argue that Landauer's Principle has not been shown to hold in general, and (...) Maroney offers a method that he claims instantiates the operation reset in a thermodynamically reversible way. In this paper we defend the qualitative form of Landauer's Principle, and clarify its quantitative consequences (assuming the second law of thermodynamics). We analyse in detail what it means for a physical system to implement a logical transformation L, and we make this precise by defining the notion of an L-machine. Then we show that logical irreversibility of L implies thermodynamic irreversibility of every corresponding L-machine. We do this in two ways. First, by assuming the phenomenological validity of the Kelvin statement of the second law, and second, by using information-theoretic reasoning. We illustrate our results with the example of the logical transformation 'reset', and thereby recover the quantitative form of Landauer's Principle. (shrink)