Overview
Belief is the map we use to navigate the world. You believe the floor will hold you, the water is safe, and your friends like you. Without belief, we couldn’t act.
Core Idea
Propositional Attitude: A mental state of having an attitude toward a proposition. “I believe that [snow is white].” You can also hope, fear, or desire that snow is white.
Formal Definition (if applicable)
Credence (Degrees of Belief): Belief isn’t just Yes/No. It’s a spectrum from 0% (Impossible) to 100% (Certain). I believe it will rain tomorrow (70%), but I believe $2+2=4$ (100%).
Intuition
- Dispositional Account: To believe X is to be disposed to act as if X is true. (If you believe it’s raining, you take an umbrella).
- Representational Account: Belief is a sentence written in the “Language of Thought” in your brain.
Examples
- Rational Belief: Based on evidence.
- Irrational Belief: Based on wishful thinking or delusion.
- Tacit Belief: Things you believe but aren’t thinking about right now (e.g., that giraffes don’t wear hats).
Common Misconceptions
- “Belief is a choice.” (Doxastic Voluntarism). Try to believe right now that you are a helicopter. You can’t. Belief is usually involuntary response to evidence.
- “Faith is the opposite of belief.” (Faith is a type of belief, often defined as belief without sufficient evidence.)
Related Concepts
- Cognitive Dissonance: The discomfort of holding two contradictory beliefs.
- Confirmation Bias: Noticing only evidence that supports your belief.
- Moore’s Paradox: “It is raining, but I don’t believe it.” (Logically consistent, but impossible to say meaningfully).
Applications
- AI: Modeling belief states in agents (BDI model: Belief-Desire-Intention).
- Psychology: CBT (Cognitive Behavioral Therapy) changes behavior by changing beliefs.
Criticism / Limitations
We often don’t know what we believe until we are tested.
Further Reading
- Schwitzgebel, Belief
- Quine & Ullian, The Web of Belief