Astatement that seems to be contradictory but proves to be true in some sense is a(n)
a) pun
b) paradox
c) epigram
d) understatement

A statement that at first appears to be contradictory but that actually contains some manner of truth is known as a paradox.  Conversely, a paradox can also begin with two acceptable starting premises and arrive at a point in which both are true to some varying degree, but also that are at once at odds with each other.