What are some real-life examples using reason (deductive or inductive) in a sound and valid manner and coming up with a false statement of reality? In other words, I'm trying to prove that reason is not always a reliable way of knowing.

How can one rationally show that life is of supreme value and that killing should be disallowed in all instances, without relying on religious axioms such as that life is "sacred" or "god given?" It appears that, without resorting to such a religious axiom, it is impossible to rationalize complete prohibition of killing, especially considering social situations which we already know necessitate taking of life, e.g. war or self-defense. If that is true, can one conclude that the prohibition of killing as it stands in modern criminal law is induced by religious motivation and not a genuine society engineering concern, and as such contradicts reasoning?

Since normal mental function is determined by mere statistics--that is to say, the concept of sanity is based on the way most people behave--is it morally acceptable to treat people with what are perceived to be mental problems?

I have an opinion I'd like some feedback on. My view on war is generally that it's a bad idea. Aggression against another country or similar entity is difficult to justify. However the fact remains that an outside force can invade and make war on your country. My opinion on this is that an invader should be destroyed completely. Ruthless exploitation of any weakness, and use of any weapon is completely justified to expel the threat, at least until they have ceased their aggression and given back any territory gained. After that it would be difficult again to justify continuing the use of ruthless tactics in an act of aggression towards your enemy in their own territory. My idea of using complete force against an aggressor comes from that you didn't make war on them. They brought war to you. For example, if you were being violently mugged, it would be justified to kill your assailant. However, it would be unjustified to go out and kill someone just because they might mug you. Or, if you were mugged and...

Can you think of a single justification for your existence that Harry Potter couldn't use? "I think, therefore I am" doesn't work, because Harry thinks, but doesn't exist.

Considering Descartes' malicious demon idea, is it possible that we could be manipulated in such a way so as all our beliefs are false? I'm thinking that we'd already need some true beliefs in order to have false ones. To be fooled into thinking that pig beards are shorter on Tuesdays I'd have to have true beliefs about pigs, beards, length, and Tuesdays for example. Can I infer then that the overwhelming majority of our beliefs must be true?

I am about to start college and plan to do either an English honours course or a philosophy honours course for my graduation. But my parents are not quite supportive of this as they think that I am working myself into a dead end and these courses won't get me a job and are completely pointless. I am unwilling to do something more "career-oriented" as my interest lies in the aforementioned subjects. Am I being impractical by doing so as I don't have any long term goals? Will I repent my choice later?

I studied philosophy in university and I recall that one of my tutors for symbolic logic was trying to walk me through a problem by saying that if you have a large enough set of premises, two of them will inevitably contradict one another. I've always had trouble understanding (and consequently, accepting) this proposition because: if one conceives of reality as a set of claims (e.g., I am right-handed, electron X is in position Y, 2 + 2 = 4, etc.) there are an infinite number of "premises" to the "argument" that is reality and consequently reality is self-contradictory. Am I missing something here? Can you explain which of us is right about this and in which sense? I should mention that I don't necessarily have a problem with reality being self-contradictory, but that really throws symbolic logic out the window (and doesn't throw it out the window at the same time)! Thanks to all respondents for their time. -JAK

Does it follow from materialism that we should be able to infer literally anything there is to know about a person's consciousness (feelings, memories, etc.) from publicly observable facts about their brain and body? If we had perfect neurological knowledge, is there anything that might yet elude our observation?

Why is question-begging considered a fallacy when it embodies a deductively valid form of reasoning?