We find ourselves to be a puzzle, Pope's "riddle of the world". Why? Are human beings intrinsically more difficult to understand than any other kind of creature? Even allowing for the complexity of the human brain that seems unlikely; all vertebrates and perhaps all nervous systems are very improbable objects. The unflattering, rainy Thursday, explanation is just that because we are humans ourselves the criteria and the standards and thresholds that we apply to an account of human action are more demanding than those that we bring to bear on descriptions focused on other organisms. We commonly say of a draughtsman or a painter that his flowers and animals are not bad, but he seems to struggle with the human form. The plants and the animals might well put it the other way around.