Physicalism is true.

Thanks, Pro. Argument for PhysicalismMy opponent has attempted to provide only one argument in attempt to shoulder the burden of proof for showing that physicalism is true. It seems to me that this argument has not only failed, but is self-defeating.My opponent originally argued something like this:Because the study of physical entities (science) does not tell us anything about non-physical entities, we can conclude that therefore non-physical entities do not exist.I showed this argument to be unsound, as the its conclusion clearly does not follow. Again, why should we think that if non-physical entities exist, the study of physical entities (science) should tell us something about them? The existence of non-physical entities is clearly not within the scope of science.In attempt to rescue this argument, my opponent backtracks and argues that science can, in fact, study non-physical entities. Aside from the fact that this statement blatantly contradicts the definition of science, even if it were true it would be self-defeating. My opponent proposes to use the existence of non-physical entities (with regard to their relationship to the hard sciences) to demonstrate that non-physical entities do not exist! But surely my opponent's own view (that hard science makes use of non-physical entities) entails that non-physical entities must exist, thus defeating physicalism.So, it seems to me that my opponent has not come anywhere close to fulfilling the burden of proof that was required of him in this debate. He has succeeded only in providing one self-defeating argument in attempt to demonstrate that physicalism is true.Arguments Against Physicalism1) Modal ArgumentIn response to this argument, my opponent has argued that S5 modal logic is false. Unfortunately, he failed to provide any justification for thinking that S5 modal logic is false, so I don't have much to work with by means of a response. In any case, he seems to be arguing that possible worlds aren't really "possible" at all. If this were true, then it seems to me that a possible world would need to be an incoherence, such as a square circle or a married bachelor. But I just don't see any reason to think that possible worlds are incoherent. I can conceive of possible worlds, which leads me to believe that these worlds are, in fact, "possible" (as opposed to a square circle, of which the incoherence is obvious as the entity in question is inconceivable). So, I don't see any reason to reject the modal argument on the grounds that S5 modal logic is false, as it seems to me that possible worlds really are "possible". In order to reject this argument, one would have to genuinely be unable to conceive of a possible world. As I myself can perfectly conceive of a possible world, I don't see any reason to think it isn't really "possible". Thus, the modal argument remains sound.2) Argument from TruthIn my second argument, I argued that if physicalism is true, then there are no true sentences. But, of course, this would be self-contradictory, which gives us reason to think that physicalism is not true. My opponent responds by arguing that sentences are physical, stating that "an utterance (of words) is a clearly physical process". I agree with this statement, but my opponent fails to understand that sentences do not necessarily need to be "an utterance". There is a clear distinction between a sentence and an utterance. A sentences is merely a complete set of words, whereas an utterance (which is physical) involves the expression of those words. So, my opponent's objection is mistaken. Thus, the argument from truth remains sound.3) Evolutionary Argument AMy opponent's objection to this argument consisted of the unwarranted assertion that evolution selects for beliefs with truth content in the majority of instances. But why think that's the case? As I previously stated, evolution is concerned only with advantageous behavior that works to maintain or increase fitness. Whether the beliefs associated with this behavior are true is utterly irrelevant. A false belief that is associated with a beneficial behavior will increase fitness just the same as a true belief that is associated with a beneficial behavior. In attempt to provide justification for his claim, my opponent states that "the need to survive" is linked to "the acquisition of truth propositions". But again, this is just another unwarranted claim in itself. What reason is there to think that the need to survive is linked to the acquisition of truth propositions? Consider "cognitive faculties A" (CFA) and "cognitive faculties B" (CFB). CFA produces evolutionary advantageous behavior along with false beliefs. CFB produces evolutionary disadvantageous behavior along with true beliefs. What reason is there to think that evolution is concerned in the slightest with the truth content of our beliefs? Clearly, CFA will be selected for, even though CFA entails false beliefs. My opponent has failed to show that evolution will select for cognitive faculties which are associated with true beliefs in the majority of instances. Thus, the first evolutionary argument remains sound.4) Evolutionary Argument BHere, I argued that concepts like kin selection and reciprocation can be used to explain seemingly altruistic behavior among animals. However, these concepts cannot (always) be used to explain this sort of behavior in human beings. My opponent states that I must provide a "coherent example of altruistic behavior that cannot be explained by evolution". I think this is fairly straight-forward. To give just one coherent example, self sacrifice (where the individual sacrificing himself is not related to the individual who is the beneficiary of the act) is an instance of altruistic behavior that cannot be explained by evolution. If this is even possible, it follows that (on physicalism) evolution must be false. But I think the argument is even stronger than that; surely there are several instances of self-sacrifice (which cannot be explained via kin selection or reciprocation) among human beings. Thus, the second evolutionary argument remains sound.ConclusionsRecall that my opponent was responsible for shouldering the burden of proof in this debate. In order to do so, he must have showed that "physicalism is true". I think it is clear that the debate resolution has not been shown to be true. My opponent provided a single argument in attempt to justify his assertion that "physicalism is true" over the course of this debate. After my refutation of this argument, my opponent attempted to reconstruct it by arguing that hard sciences make use of non-physical entities, an argument which itself requires the existence of non-physical entities. So, it seems to me that my opponent has not only failed to provide justification for claiming that "physicalism is true", but has put forward a self-defeating argument.In contrast, I have provided four sound arguments against physicalism. Remember that even if each of these four arguments were knocked down, my opponent would still have all of his work ahead of him in fulfilling the burden of proof by providing justification for the assertion that "physicalism is true". However, at this point of the debate it seems that each of my four arguments remain standing. As the only argument provided in favor of physicalism has been refuted, and the four arguments against physicalism remain standing, it seems to me that we can reasonably conclude that my opponent has failed to justify his assertion and the debate resolution that "physicalism is true".I'd like to thank my opponent for creating and participating in this debate. I'd also like to thank everyone who took the time to read it through.Sourceshttp://isites.harvard.edu...http://www.plosone.org...http://dictionary.reference.com...http://www.merriam-webster.com...http://www.thefreedictionary.com...http://www.oxforddictionaries.com...http://dictionary.cambridge.org...