[I]f PSR [the principle of sufficient reason] is wrong and there are uncaused events, what happens to the imperative to seek causes? Should scientists and others now stop looking for them? Not at all. To seek causes does not commit us to believing there must always be a cause for us to find, no more than seeking gold commits us to supposing there will always be gold where we hope to find it. Often there will not be. On such occasions the better part of wisdom is to admit it and look elsewhere. Science does not presuppose PSR, even though science is an enterprise dedicated in large part to seeking causes.
John Post, Metaphysics: A Contemporary Introduction, New York, 1991, pp. 66-67