A philosophy PhD student writes:
My inclination is to think the best bet is to ask faculty in your department who are expert in the area, but I imagine many readers would benefit from the experience of others on this front.
[W]hat is the surest way of knowing that one's idea for a philosophy paper is original? I have often found myself frantically looking up possible titles of papers/books with similar ideas to mine on Google scholar, philosopher's index etc., and, conducting an almost identical search months later, new entries always seem to creep in. Is that just about the best one can do, apart from talking to experts in relevant fields?