Yes it is. But now I suppose you expect me to say how. You are asking a lot. Here are a few tips. (1) Look for a question that is small but not trivial. It’s often a good idea to look for a question that is about a specific argument for a big claim, rather than a question directly about the big claim itself. This gives you focus and specificity. It also gives you automatic structure, since it gives you the distinction between the issue of whether the premises are acceptable and the issue of whether the conclusion follows from the premises. (2) Look for a question that is relatively clear (though you may still need to spend a lot of effort making it clearer). (3) Look for a question that immediately suggests different readings that you can distinguish. More generally, look for a question that will enable you to make useful distinctions. (4) Look for a new question that looks like an old question that...

I suspect that many of us suffer from your incoherent-footnote-to-Plato worry from time to time, but let me say two encouraging things. The first is that although philosophy does often circle back to issues and arguments in its own history, when we consider them anew we consider them in a new context, and this makes room for originality. Of course it helps not to expect too much. You don't have to provide a definitive reply to scepticism about the external world: it's glory enough to push the discussion along in smaller but still productive ways. The second encouragin thing to say is that originality isn't everything. Even if it turns out that someone else had the idea centuries ago, working things out for yourself has a special intellectual value for you. Philosophy is not a spectator sport.

Here is an additional (and very ahistorical) reason for studying some history of philosophy. The best philosophers of the past had more philosophical talent than any philosopher now living.

I think that almost all of the central figure in the western philosophical canon would have considered themselves philosophers, though not necessarily academic. Some of them were also notable for other things -- for example Aristotle for biology and Descartes and Leibniz for mathematics. There have also been great scientists who might not have considered themselves philosophers but did some significant philosophical writing -- for example, Galileo, Boyle, Newton and Einstein. But perhaps one shouldn't put too much emphasis on disciplinary affiliation. And even if one is in the first instance a philosopher, it is a real plus if philosophy is not the only thing you know about since (among other things), so much philosophy is Philosophy of X, where X is some other discipline.

Fortunately, I never thought I would try to be the next Plato or Socrates. I was originally attracted to philosophy because I thought that it asked particularly basic questions, questions that where underneath a lot of the other questions people ask. (I felt somewhat similarly about physics.) When I started studying philosophy seriously as an undergraduate, I wasn't disappointed. I really enjoyed the issues and the arguments, and I didn't mind that we kept circling back to the same big questions without ever definitively answering them. Maybe it's a case of arrested development, but these feelings and pleasures have stayed with me.

You have probably asked the wrong website, since the 'Philosopher' in 'the Philosopher's Stone' does not refer to a philosopher but to a scientist, or an alchemist. The term 'scientist' was only invented in the 19th century; Newton was a 'Natural Philosopher'. And in fact Newton himself was centrally concerned with the search for the Philosopher's Stone. For Newton put an enormous effort into alchemy, and the Philosopher's Stone is what the alchemists were looking for, a substance that would convert base metals into gold. There is alas no reason to believe this substance exists. Transmutation of elements does occur -- think of radioactivity -- but we've no way to convert lead into gold.

Here is one reason why one limited form of competition in philosophy (and many other areas of inquiry) is good. Faced with a philosophical problem, our best bet is to propose a possible solution, criticise it, and on that basis to try to improve it, or improve on it. But almost all philosophers are better at criticising other people's ideas than their own. So competition yields an epistemic advantage. Karl Popper proposed this kind of methodology of 'conjectures and refutations' as the key to inquiry, especially in science. Although there is a lot I would criticize (sic) in Popper, I think he is right to emphasise the importance of trying to find the weak points in the best ideas people can come up with.

You might look at some philosophers' autobiographies. Some of these are disappointing, but two that aren't are John Stuart Mill's Autobiography and Anthony Kenny's A Path from Rome .