When your mind is going hither and thither, discrimination will never be brought to a conclusion. With an intense, fresh and undelaying spirit, one will make his judgments within the space of seven breaths. It is a matter of being determined and having the spirit to break right through to the other side.
This particular passage from Hagakure seems to have been quoted thousands of times before, but it was new to me. Sound advice from the past, still relevant in the present.