Mr. Sommerville was one of my high school teachers. I took his philosophy class, and even though I got a D, I felt that was one of the most influential classes I'd ever taken, aside from drama & food studies.
He had mentioned that he was an atheist in our first class. I couldn't picture an atheist before him, so when I think of the first one, he comes to mind.
My only real debate with him was when he said "Oh my god" or "good god", using god in his exclamations, so when I pointed this out, he said that it's actually blasphemous for a believer to use such language, and since he isn't one, it's okay.
Since then, I can't help but feel that using the word of god would make people think I was a believer.
Anyway he was my first.
Atheist, that is.