The concept of property has a long tradition and it is widely accepted as a regulation scheme to allocate tangible scarce resources. Supporters of intellectual property rights tend to base their argumentation on traditional property rights theories as proposed by John Locke, Georg Wilhelm Friedrich Hegel and Jean-Jacques Rousseau. This presentation focuses on the question, whether Locke‘s labor appropriation theory can be applied to non-material goods. 
   The results show that despite the fact that labor provides a strong connection between individuals and resources it widely fails to justify appropriation of non-material goods. Strong Lockean property rights in ideas must be refuted since they would harshly interfere with other civil liberties such as free speech, which Locke himself found extremely important. Furthermore, even partial appropriation seems problematic, given that private ownership is a precondition for efficient material production but not for the production of intellectual goods. 
   Since intellectual production is a social endeavor and creation ex nihilo is implausible intellectual laborers may only (partly) appropriate the fruits of their labor but not the entire value of their final produce. 

• Locke argues that individuals are entitled to exclusively possess a resource to secure the production process. Given that intellectual production does not depend on exclusive ownership, intellectual resources remain in the public domain.

• It is only justified to appropriate the fruits of one’s own labor, not those of others. This finding seems to be particularly controversial, given the prevalent practice of companies seizing the ideas of their employees.

• Appropriation of ideas must not hinder other people to appropriate their own share. Furthermore, this pool of intellectual goods must be bigger than the pool, which people could expect in a natural state, in which an intellectual property regime is absent.