What is Philosophy?

I want to focus on two things Deleuze talked about: truth and discourse.  He attacks the fact that people search for the truth from a preconceived notion, from a certain disposition. As if truth was somehow a balloon and it was tied to a ribbon, which was tied to say, a chair, on the other end. "Truth" can only go certain ways, and can only reach out so far when it is trapped within that discourse. This makes sense to me, but I wondered, how can we escape that?