Abstract: A natural language logic is based on the grammar of the language. Chinese logic, which is based on Chinese grammar, is thus different from Greek logic. Isostructural reasoning is universal to human species as it has a biological origin. Chinese people, however, are especially good at and fond of making isostructural inference because the isostructural principle in Chinese grammar has shaped the way Chinese people think and reason, which is reinforced by the homophonic association mechanism in Chinese linguistics. These linguistic factors have contributed to the isostructural reasoning. Isostructure and root-branch function as the two main categories of thinking in Chinese logic. In addition, isostructural reasoning and comparative reasoning constitute the two fundamental procedures of Chinese reasoning.

Key words: isostructural reasoning, Chinese logic, isostructural grammatical principle, homophonic association of ideas