rationalism

2. A belief that reason is the main source of knowledge, more important than feelings or experience.

The philosopher wrote a book about rationalism and how the mind discovers truth.

3. In design or planning, the practice of making things clear, simple, and based on logic.

The new building shows rationalism because every part has a clear purpose.

4. A way of thinking that trusts facts and careful thought over old stories or guesses.

Her rationalism helped the team choose the best plan instead of guessing.