Extraordinary passage from Blessed Cardinal Newman :

By sinning, by suffering, by correcting ourselves, by improving ourselves, we advance towards the truth by the experience of error; we achieve success through failure. We do not know how to act well except after having acted badly. […] We know what is good not positively but negatively; we don't see the truth all at once to go towards it, but we throw ourselves on the error to experience it, and we discover that it is not the truth. […] This is the mechanism by which we achieve success; we walk towards the sky backwards; we aim our arrows at a target and think that he is most skilful who misses the fewest.