先秦邏輯史以往研究方法以歷史發展為脈絡，以家派為單元，以範疇研究為核心，關注表達形式與論證結構，常以西方邏輯為參照系，有相當的研究成果，也有一定的限制。本文分析先秦諸子推理的類型、範圍與方法；在研究方法上提出思想單位作為分析單元，指出思想單位的結構與內涵要件，並說明思想單位在推理過程中的遞演關係。其中，「理」可分為「所依之理」的推論形式規則，以及「所據之理」的含蘊理則；思想單位的結構有情境構作、情境處理與情境融合；先秦邏輯之推理目的有：認知、說服；推理方式有：內推、外推、由內而外等，各思想單位依理、據理而推展。

In the past, the study of the history of logic in pre-Qin period took historical development as the context, schools as the unit, and category research as the core, concentrating on the forms of expressions and the demonstration structure, while taking Western logic as the frame of reference. Substantial research results have thus been acquired, yet certain limitations have also been in place. This paper analyzes the types, scopes and methods of pre-Qin philosophers’ reasoning. In addition to bringing up thought unit as the unit of analysis for research, the paper points out the structure and connotation of a thought unit and illustrates the development of a thought unit in the process of reasoning. “Rule” can refer to the inferring principle for the logic rule, as well as the implicative principle for the paradigm of structure. The structure of a thought unit includes context construction, context processing and context integration. The purposes of pre-Qin’s logical reasoning are cognition and persuasion. The reasoning methods are: interpolation, extrapolation, from the inside to the outside, etc. Each thought unit is reasoned according to logic rules and structure paradigms.