Physicalism is true.

Thanks, Pro.RebuttalMy opponent's first argument resulted in the conclusion that the non-mental must exist. I requested that my opponent focus his arguments on showing that dualism is false (as my opponent and I agree that showing idealism to be false does not show physicalism to be true). I don't think this argument requires any more discussion, as my opponent and I agree that the non-mental exists. Let's move on to the second argument then.In his second argument, my opponent concludes that "all actually existing entities are physical." He attempts to justify this claim by stating that because the hard sciences tell us nothing about immaterial entities, those immaterial entities must therefore not exist. So, if we take science to be the study of the material world, my opponent's argument can be summed as follows: Immaterial entities do not exist because the study of the material world (science) tells us nothing about such entities. I think it can be plainly seen that this argument is unsound. If immaterial entities existed, why should we expect the study of the material world to tell us so? My opponent responded by arguing that science is not limited to the study of the material world, saying that this thinking was a result of "only basic science education". I'll first note that science is by definition the study of the material world:Science: systematicknowledgeofthephysical or material worldgainedthroughobservationandexperimentationhttp://dictionary.reference.com...Science: knowledge about or study of the natural world based on facts learned through experiments and observationhttp://www.merriam-webster.com...Science: Suchactivitiesrestricted to a class of natural phenomenahttp://www.thefreedictionary.com...Science: The intellectual and practical activity encompassing the systematic study of the structure and behavior of the physical and natural world through observation and experimenthttp://www.oxforddictionaries.com...Science: the systematic study of the structure and behavior of the natural and physical world, or knowledge obtained about the world by watching it carefully and experimentinghttp://dictionary.cambridge.org...Moreover, if my opponent wishes to argue that science is not restricted to the physical world, he must concede that non-physical entities exist, thus defeating his own argument. It follows that if science involves the study of non-physical entities, then non-physical entities must exist. My opponent has put forward a self-defeating argument.Arguments Against Physicalism1) Modal ArgumentRecall that I presented a modal argument against physicalism, where A is "me" and B is "my body":Premise 1: If physicalism is true, then the proposition A=B must be true.Premise 2: The proposition A=B is not true.Conclusion: Physicalism is not true.Justification for the premises of this argument can be found in round 2 (I don't think it's necessary to regurgitate them).My opponent argues that perhaps S5 modal logic is false and it is TRIV modal logic that ought to be considered. I'll have to ask that my opponent take issue with a specific premise of the argument rather than simply stating that S5 modal logic is false. It seems to me that in order to reject this argument's conclusion, one would need to argue that it is not possible that I (A) should exist independently of my body (B). But surely this is possible, as it can be easily conceived (see round 2). 2) Argument from TruthPremise 1: If physicalism is true, there are no true sentences.Premise 2: Premise 1 is true.Conclusion: Therefore, physicalism is not true.I'd assumed that the premises of this argument were self-explanatory to the point where my opponent would be capable of identifying any issue he might have with the argument without further explanation being necessary. At his request, however, I'm happy to provide justification for the premises. P1: A true sentence is itself an non-physical entity. As physicalism affirms that non-physical entities cannot exist, it follows that if physicalism is true then true sentences (non-physical entities) do not exist.P2: If we assume premise 1 to be true, we assume "if physicalism is true, there are no true sentences" to be a true sentence. This, of course, is self-contradictory.Conclusion: As a result of this self-contradiction, we can conclude that physicalism is not true.3) Evolutionary Argument APremise 1: If the conjunction of evolution and physicalism is true, then the reliability of our cognitive faculties is low.Premise 2: If the reliability of our cognitive faculties is low, then we cannot sensibly hold any beliefs produced by these cognitive faculties, including the belief that physicalism is true.Conclusion: If the conjunction of evolution and physicalism is true, then we cannot sensibly believe that physicalism is true.Please see round 2 for justification of premises. My opponent argues that this argument "only considers examples where evolution is detrimental to truth acquisition and never considers examples where evolution benefits truth acquisition." This is false. As I stated in round 2, we can say that there is a 50% probability of any given belief being true. This means that for any belief, the chances of that belief being true are just as likely as the chances of that belief being false. I have used examples where evolution is detrimental to truth acquisition. Rather, I have argued that evolution is indifferent to truth acquisition. This is a crucial distinction that must be understood in order to comprehend the argument. My opponent goes on to argue that he thinks evolution "selects for true beliefs more than it does for false beliefs". Does he have any sort of justification for this? As I stated in round 2, evolution is concerned only with advantageous behavior. As such, the truth content of beliefs is completely irrelevant so long as these beliefs (true or false) produce behavior that maintains or increases an organisms fitness. The claim that evolution "selects for true beliefs more than it does for false beliefs" remains an unwarranted assertion, perhaps resulting from the desire to trust one's own cognitive faculties. 4) Evolutionary Argument BPremise 1: If the conjunction of evolution and physicalism is true, then altruism cannot exist.Premise 2: Altruism exists.Conclusion: The conjunction of evolution and physicalism is not true.Please see round 2 for justification of premises.My opponent argues that this argument holds sound "only if you ignore other possible evolutionary explanations of such behaviors". Oddly enough, my opponent fails to propose such an alternative explanation. All evolutionary explanations can be divided into subsets of either kin selection or reciprocation. For example, group selection can be considered a subset of kin selection (or vice versa) and direct, indirect, and network reciprocation can each be considered subsets of reciprocation. http://www.plosone.org...http://isites.harvard.edu...If my opponent wishes to propose an alternate explanation of altruistic behavior among human beings, then I'll gladly consider it. I think this is highly unlikely as there are no prominent explanations for altruism with the exceptions of kin selection, reciprocation, and the subsets of these explanations (none of which provide an explanation for certain types of altruism displayed by humans). Until an alternate explanation is discovered, we can reasonably conclude that there is no physical explanation for altruism among human beings.SummaryRecall that my opponent is responsible for shouldering the burden of proof in this debate. As much, he must provide justification to think that physicalism is true. Thus far, my opponent has provided two arguments, each of which have been addressed. The first of these arguments only showed that non-mental entities existed. My opponent conceded that this argument was not intended to justify the assertion that "physicalism is true". What about my opponent's second argument? Here, he argued that the study of the physical world (science) tells us nothing about non-physical entities, and that therefore non-physical entities must not exist. I showed that there is no reason to think that if non-physical entities existed, the study of the physical world (science) should tell us something about them. My opponent then put forward a self-defeating argument which attempted to show that science is not limited to the study of the physical world (if this were true, it would entail the existence of non-physical entities, thus defeating the debate resolution). In contrast, I have provided four sound arguments to think that physicalism is not true. Remember that even if each of these arguments were to be defeated (which I think is unlikely) my opponent would still have all of his work in front of him in attempting to justify the assertion that physicalism is true.For now, then, we can reasonably conclude that there are no good reasons to think that physicalism is true, while there are four good reasons to think that physicalism is not true.Thank you.Sourceshttp://dictionary.reference.com...http://www.merriam-webster.com...http://www.thefreedictionary.com...http://www.oxforddictionaries.com...http://dictionary.cambridge.org...http://www.plosone.org...http://isites.harvard.edu...