First, if you need help finding a topic in philosophy, you might want to consult these reference books for overview essays:

• Stanford Encyclopedia of Philosophy (see below link).
• The Encyclopedia of Philosophy. New York: Macmillan, 1967. 8v. Reference B 41 .E5.
• Dictionary of the History of Ideas: Studies of Selected Pivotal Ideas. New York: Scribner, 1973. 4v. + index.  Reference CB5 .D52.
• Dictionary of World Philosophy.  New York: Routledge, 2001. Online through Credo Reference.

Once you have a topic in mind, try searching in these databases that specialize in philosophy:

• Internet Encyclopedia of Philosophy (see below link)
• PhilPapers
• Poiesis: Philosophy Online
• Philosopher's Index with Full Text

Searching Tip: Using the word response or reply  in the search box, combined with your topic keyword may help pull up articles that are responding to another on that same topic. You may then need to go track down the original article.