“As sociologists are fond of pointing out, many of these aphorisms appear to be direct contradictions of each other. Birds of a feather flock together, but opposites attract. Absence indeed makes the heart grow fonder, but out of sight is out of mind. Look before you leap, but he who hesitates is lost. Of course, it is not necessarily the case that these beliefs are contradictory—because we invoke different aphorisms in different circumstances. But because we never specify the conditions under which one aphorism applies versus another, we have no way of describing what it is that we really think or why we think it. Common sense, in other words, is not so much a worldview as a grab bag of logically inconsistent, often contradictory beliefs, each of which seems right at the time but carries no guarantee of being right any other time.”