...an external reward can affect one's interpretation of one's own motivation, and interpretation that comes to be self-fulfilling. A similar effect may account for the familiar fact that when someone turns his hobby into a business, he often loses pleasure in it. Likewise, an intellectual who pursues an academic career gets professionalized, and this may lead him to stop thinking. This line of reasoning suggests that the kind of appreciative attention where one remains focused on what one is doing can arise only in leisure activities. Such a conclusion would put pleasurable absorption beyond the ken of any activity that is undertaken for the sake of making money, because although money is undoubtedly good, it is not intrinsically so.

Autor: Matthew B. Crawford