Something is true or false only if we believe it to be so.

How post-modernist of you. For those of us with an actual education, the difference between 'truth' and 'belief' is like the difference between science and religion. Whether or not you believe the Earth is round, it is anyway; your belief is not required for this to be true. Realizing that the truth of reality might be different from your beliefs, and pursuing the truth anyway, is part of what it means to be a scientist.