General concepts:
* Philosophy of life: This is the most direct and comprehensive term. It encompasses a person's beliefs about the meaning and purpose of life, guiding their actions and worldview.
* Worldview: Similar to philosophy of life, but with a broader emphasis on how someone perceives and interacts with the world, including their values, beliefs, and assumptions.
* Life purpose: This focuses specifically on the individual's sense of meaning and mission in life.
More specific options:
* Ideology: If the belief system is more structured and systematic, with a strong emphasis on social and political implications.
* Ethos: Focuses on the character and values that underpin a person's actions and how they influence the culture around them.
* Spirituality: If the beliefs are deeply personal and connected to a higher power or spiritual realm.
Other possibilities:
* Mission statement: This is a more formal term, often used in business or personal development, but it can describe a person's guiding principles.
* Code of conduct: More specific and emphasizes the rules and principles a person lives by.
The best word will depend on the specific context and the nuances you want to highlight.