a hundred schools of thought contend (idiom); refers to the classical philosophic schools of the Warring States period 475-221 BC
Definitions (粵典–words.hk)
語句
指社會上充滿各種不同思想流派、著作學説，學術上蔚為一片繁榮景象，可以指春秋戰國時代、中華人民共和國立國初嘅現象 the phenomenon when there are many scholars, ideologies publishing and bringing up discussions; literally: hundred schools air views
Definitions (Wiktionary)
phrase, idiomatic
to let a hundred schools of thought contend
phrase, idiomatic
contention of the Hundred Schools of Thought