 As various forms of Buddhism dominated the medieval period of Japanese philosophical history, so did Buddhist estimations of words and meaning come to inform the minds of many of the philosophically inclined. While some aspects of Rinzai Zen esteemed components of traditional Chinese arts and letters, the more central spiritual praxis was more renowned for its their anti-intellectualism. This latter stance was well expressed in the use of kōan, or paradoxical exchanges meant to facilitate realization of Buddha-nature. The gist of the Zen teachings was that words, at best, are mere conventions useful for everyday communication. The transitory, insubstantial way of things (suchness or emptiness) cannot be adequately captured by the fixed meanings of conventional language. When transmitted from teacher to disciple, the highest level of truth could only be conveyed in a mind-to-mind transmission, one that typically eluded simple discursive language.