The article argues that property theory should focus more on intangible property, like ideas and inventions, not just physical things like land. Intangible property is becoming more important in our economy and daily lives. The current understanding of property can include intangible things. The article suggests that property theory has mostly focused on physical property because of tradition. Paying more attention to intangible property could help us understand how property works in modern cities and how it can help with new technologies.