The argument that I think you're making in your first paragraph is fallacious. In particular, it can happen that (1) <i>everyone</i> wants to give some money to the poor but (2) if they all have to do it individually (rather than a universal tax) no one will do it. This will happen, for instance, if everyone strongly dislikes being worse off than their neighbours, but weakly prefers that the poor be helped. (This is the same idea as in the familiar situations of "prisoners' dilemma" and "tragedy of the commons". It's also why some sports have officially-enforced requirements for safety measures: everyone's better off if everyone's protected, but if it's optional then that's at best an unstable equilibrium because a player or team that chooses to forgo the protection may get an advantage over those who don't. But once no one is protected, all those competitive advantages go away and everyone's worse off than if everyone had been protected.)<p>Now, if (as your second paragraph suggests) you really believe that taxation is so fundamentally evil that it cannot be justified whatever its good consequences, then of course the above will leave you entirely unmoved. But if you are prepared to consider trading off harms against benefits, then I don't think you're entitled to dismiss the possibility that some redistributive taxation is a good thing overall; in particular, you can't just say "if people want to give money to the poor then let them do so" unless you have good reason to think that the sort of situation I described above doesn't obtain.