noun, noun which may take the genitive case particle 'no'
Refers to the philosophical doctrine or a general attitude of pursuing ideals, often contrasted with realism.
彼は理想主義に基づいて行動している。
He acts based on idealism.
理想主義的な考え方は時に
Idealistic ways of thinking sometimes clash with reality.
Compound of 理想 (ideal) + 主義 (doctrine, -ism). The term is a calque from Western philosophical vocabulary.