Every truth is a path traced through reality: but among these paths there are some to which we could have given an entirely different turn if our attention had been orientated in a different direction or if we had aimed at another kind of utility; there are some, on the contrary, whose direction is marked out by reality itself: there are some, one might say, which correspond to currents of reality. Doubtless these also depend upon us to a certain extent, for we are free to go against the current or to follow it, and even if we follow it, we can variously divert it, being at the same time associated with and submitted to the force manifest within it. Nevertheless these currents are not created by us; they are part and parcel of reality.

Henri L. Bergson -- The Creative Mind: An Introduction to Metaphysics, p. 218

ETA: retracted. I posted this on the basis of my interpretation of the first sentence, but the rest of the quote makes clear that my interpretation of the first sentence was incorrect, and I don't believe it belongs in a rationality quotes page anymore.