Interpreters have long recognized that there is a problem about determining what kind of activity Aristotle thinks happiness is. Some of his remarks appear to favor a single best kind of activity, intellectual contemplation. Other evidence suggests that it is an overarching activity that has various virtuous activities, ethical and intellectual, as parts. Interpreters typically view these as incompatible theses and try to show that one or the other apparent thesis is merely apparent. The problem of determining which of two incompatible theses Aristotle believes is the Dilemmatic Problem of Happiness. But the arguments that rival interpretations amass exert pressure to think that Aristotle really is committed to both of the allegedly incompatible claims. The problem of showing how he can coherently endorse both is the Conjunctive Problem of Happiness. Any dialectically satisfactory interpretation of Aristotles theory of happiness must solve it. None has done so. It cannot be solved while laboring under the weight of three common assumptions. Chapters 2–4 argue for the falsity of those assumptions and provide materials for constructing a solution to the Conjunctive Problem.

It is standardly believed that Aristotle thinks that there are two kinds of happiness, one corresponding to intellectual contemplation and the other corresponding to ethically virtuous activities, and the former kind is superior to the latter. This is the Duality Thesis. It is notoriously problematic and does not follow from anything that Aristotle has said to that point. It also prevents solving the Conjunctive Problem of Happiness. Interpreters have felt forced to affirm the Duality Thesis by its apparent textual inescapability. However, the apparent claim depends on supplying “happy” or “happiest” from the previous sentence, as is standard among translators and interpreters. I argue for an alternative supplement that commits Aristotle to a much less problematic and unexpected position.