In using the terms play and playfulness, I do not intend to suggest any lack of seriousness; quite the contrary. Anyone who has watched children, or adults, at play will recognize that there is no contradiction between play and seriousness, and that some forms of play induce a measure of grave concentration not so readily called forth by work.
The intellectual’s ... playfulness, in its various manifestations, is likely to seem to most men a perverse luxury; in the United States the play of the mind is perhaps the only form of play that is not looked upon with the most tender indulgence. His piety is likely to seem nettlesome, if not actually dangerous. And neither quality is considered to contribute very much to the practical business of life.Richard Hofstadter
It is hard to write a simple definition of something as varied as hacking, but I think what these activities have in common is playfulness, cleverness, and exploration. Thus, hacking means exploring the limits of what is possible, in a spirit of playful cleverness. Activities that display playful cleverness have "hack value".richard m. stallman