Rationalist (noun)

1. A person who believes in using reason and logic as the basis of understanding and knowledge.
2. A person who emphasizes the use of reason and scientific method in understanding the world.

Origin:

From the latin word "ratio" meaning "reason".

Examples:

1. As a rationalist, he rejected the idea of relying on faith and instead sought knowledge through observation and logic.
2. The philosopher was a rationalist who believed that knowledge could be acquired through reason and logic.
3. The scientist was a rationalist who proposed that knowledge is acquired through observation and experimentation.
4. The rationalist approach to understanding the world is based on using reason and logic as the basis of knowledge.
5. The rationalist's argument is that reason and logic are the best means of understanding the world.