In seeking to understand what lies behind the court's apparent eagerness to grant property in intellectual products, a helpful starting place would seem to be the labour theory of property found in Locke's SECOND TREATIES OF GOVERNMENT. Speaking most generally, the theory suggests that a person who successfully uses his to her efforts to make useful those things which no one else has used or claimed may be rewarded with ownership of the things. The common law has long used a simpler variant of such a principle, awarding ownership to those who take possession of unclaimed physical resources. Creators of new ideas and literary writings would seem to be creating something out of nothing, and thus would seem to be usually meritorious candidates for such rewards.
Wendy J. Gordon, Outline of Desert Theory: The No-Harm Notion (1985).