Answer by taking a quote from the following article:

Stallman was born to Alice Lippman, a school teacher, and Daniel Stallman, a printing press broker, in 1953 in New York City. Stallman had a difficult relationship with his parents, as his father had a drinking habit and verbally abused his stepmother. He later came to describe his parents as "tyrants". He was interested in computers at a young age; when Stallman was a pre-teen at a summer camp, he read manuals for the IBM 7094.

Stallman places great importance on the words and labels people use to talk about the world, including the relationship between software and freedom. He asks people to say free software and GNU/Linux, and to avoid the terms intellectual property and piracy (in relation to copyright). One of his criteria for giving an interview to a journalist is that the journalist agree to use his terminology throughout the article. He has been known to turn down speaking requests over some terminology issues.  Stallman argues that the term "intellectual property" is designed to confuse people, and is used to prevent intelligent discussion on the specifics of copyright, patent, trademark, and other laws by lumping together areas of law that are more dissimilar than similar. He also argues that by referring to these laws as property laws, the term biases the discussion when thinking about how to treat these issues.  These laws originated separately, evolved differently, cover different activities, have different rules, and raise different public policy issues. Copyright law was designed to promote authorship and art, and covers the details of a work of authorship or art. Patent law was intended to encourage publication of ideas, at the price of finite monopolies over these ideas - a price that may be worth paying in some fields and not in others. Trademark law was not intended to promote any business activity, but simply to enable buyers to know what they are buying.  An example of cautioning others to avoid other terminology while also offering suggestions for possible alternatives is this sentence of an e-mail by Stallman to a public mailing list:  I think it is ok for authors (please let's not call them creators, they are not gods) to ask for money for copies of their works (please let's not devalue these works by calling them content) in order to gain income (the term compensation falsely implies it is a matter of making up for some kind of damages).

What else did he believe in?
Stallman argues that the term "intellectual property" is designed to confuse people,