Of course there are limits to what you can choose to believe - I couldn't choose to believe that the earth is flat, even if I wanted to - but within limits, one certainly can choose one's beliefs: as I pointed out earlier, if belief or non-belief in something seems equally valid, one can choose to believe or not. I have a book called 'Religious Belief and the Will' by Louis P. Pojman which deals at length with this very question. I've had it for years, but have never got round to reading it. I will now do so, and report back.