Does Aristotle in the Nicomachean Ethics give one consistent answer to the question what life is best or two (at least) mutually inconsistent answers? In the First Book (E.N. I) he says that we can agree to say that the best life is eudaimonia or eupraxia (well-being or well-doing) but must go on to say in what eudaimonia consists (1097b22–24). By considering the specific nature of man as a thinking animal he reaches a conclusion: eudaimonia, the human good (agathon), is the activity of soul (psuchē) in accordance with virtue (aretē), and if there are more than one virtue in accordance with the best and most complete (teleia), and (since one swallow does not make a summer) in a complete life (1098a16–20). Aristotle states that his formula is no more than a sketch or outline (perigraphē), but that a good sketch is important since, if the outline is right, anyone can articulate it and supply details. He seems to be thinking here not just of the rest of his own treatise but of the work of pupils and successors; he speaks, as at the end of the Topics, of progress in a science.