There is no duty we so much underrate as the duty of being happy.

In An Apology for Idlers, collected in Virginibus Puerisque, Robert Louis Stevenson calls happiness an underrated duty. The surrounding discussion explains the social dimension of the claim: a cheerful presence can benefit people who happen to encounter it. The sentence is therefore not simply an instruction to pursue private pleasure. It asks what an enjoyable life can contribute to the atmosphere shared with others.

The word duty needs a gentle reading. Happiness cannot always be commanded, and unhappiness is not a moral failure. Stevenson's useful provocation concerns the assumption that only visible labor counts as a contribution. Humor, ease, and pleasure can also make a day more bearable for someone nearby. The essay gives those apparently unproductive effects a place in the account. A person need not apologize for every enjoyable hour on the grounds that it failed to produce something suitable for a report.

The orange cat rolling comfortably in sunlight makes that unreported benefit easy to understand. The animal is doing very little that a productivity chart could reward, yet the picture is pleasant to meet. Its unguarded comfort becomes part of the viewer's moment. Stevenson gives us a reason to notice such small exchanges: an afternoon can offer something to the world without first proving that it has been busy.