noun
Philosophical term referring to the doctrine that reason is the chief source of knowledge, or the practice of basing opinions and actions on reason rather than emotion or religious belief.
彼の考え方はラショナリズムに基づいている。
His way of thinking is based on rationalism.
The native Japanese equivalent of 'rationalism', more common in everyday philosophical discussion. ラショナリズム is a direct loanword and may carry a slightly more Western or academic nuance.
Loanword from English 'rationalism'.