郎尼根《洞察》第十四章第四節〈形上學方法的辯証〉先後從不同角度評論六套方法——壹、演繹法，貳、懷疑法，參、經驗論，肆、常識折衷主義，伍、黑格爾式辯証，陸、科學方法與哲學——之得失。茲按所作評論、分別以六篇文章來對各方法論逐一作檢討、以闡釋其中要義。本文內容將以其中之壹、演繹法作為反思主軸。演繹法意謂從原初命題演繹引申命題，其中再分抽象演繹與具體演繹。演繹法在強調嚴格推理當中仍難以証實原初命題之確實性。

One of the procedures in Lonergan’s method for metaphysics is to have dialogue with various methodologies in philosophy as well as in science so as to pinpoint the most appropriate steps in metaphysical reflection. In Insight, ch.14, §4, Lonergan consecutively makes comments on Deductive Methods (4．1), Universal Doubt (4．2), Empiricism (4．3), Common-sense Eclecticism (4．4), Hegelian Dialectic (4．5), and Scientific Method & Philosophy (4．6), respectively evaluating their achievements and weaknesses. Hereby, we will attempt to present six different essays, one on each of the above mentioned topics, with the intention of expounding on the insights which Lonergan wishes to impart to us. The present essay mainly concentrates itself on Lonergan’s view with regard to Deductive Methods.