| Noun | 1. | rationalism - (philosophy) the doctrine that knowledge is acquired by reason without resort to experiencephilosophy - the rational investigation of questions about existence and knowledge and ethics | |
| 2. | rationalism - the theological doctrine that human reason rather than divine revelation establishes religious truthdeism, free thought - the form of theological rationalism that believes in God on the basis of reason without reference to revelation | |
| 3. | rationalism - the doctrine that reason is the right basis for regulating conduct | |