The philosophy of ascetism is characterized by placing constraints on oneself in order to live a more fulfilling, or disciplined life.

[A]scetics maintain that self-imposed constraints bring them greater freedom in various areas of their lives, such as increased clarity of thought and the ability to resist potentially destructive temptations. Wikipedia

In this context, contraints are a way of gaining freedom, as paradoxical it may sound. Here are some examples of how constraints provide freedom:

• Artists frequently use constraints to narrow their focus. It allows them to work on different techniques, or use a medium they may not be as comfortable with. It gives them the freedom they need to maximize their creativity.
• Both digital minimalism (coined by Cal Newport) and ascetic computing (I first heard about it from Dave Gauer), are philosophies about interacting with computers in a deliberate manner. Computers are the most powerful machines ever created; they are capable of anything they are programmed to do, which is frequently abused in order to produce manipulative software. Choosing to use technology in an intentional way provides freedom from bad software, and allows users to experience the good parts of computing.

Sometimes the most freeing thing can be setting limits.

• Ascetism (Wikipedia)
• Ascetic Computing - Dave Gauer