人的心神可以認知常道。人在知道以前先必觀『道惡乎在』？觀道的方法，聖多瑪斯提出五路論證。多氏五路論證的思想背景，首先受希臘哲人柏拉圖分享至善，靜觀理念的啟發，柏氏認為有一至善之物的存在，此物可死後才能完全得到此物，基於人分享至善，今生藉著回憶及辯証法能不完全地或間接地以沈思或靜觀（Contemplation），獲得此至善物。亞里斯多德則彰顯靜觀生活似神明，是天地性，人最貴的理性德行，引人獲取至福。五路論證次則受聖經思想的啟迪，智慧書肯定：「從受造物的偉大和美麗，人可以推想到這些東西的創造者。」其實五路論證的軌跡在多氏闡釋聖若望福音第一章中的三種靜觀中，約可窺其端倪。五路論證第三則充斥著道明會士表詮之路及拾級而豋的靜觀修持的特色。最後當然來自聖多瑪斯個人的綜合天才。 從形上學發展來看，多瑪斯由於運用亞里斯多德類比（Analogy），謂「萬有」beings都是存有者being；多氏更大膽地採用了新柏拉圖主義的分享觀（The Notion of Participation），看出「存有者」beings分享了存有Being的「完美」，故其完美性即有限即無限，使有限存有得以往上通向無限的康莊大道。於是在分享形上學及類比方法下，透過理性對潛能，實現；因果律等原理的運用，多瑪斯架構起他的五路論證學說。 靜觀修持是領悟五路論證不可或缺的工夫，按多氏觀點，我人可以經由景像靜觀，因果靜觀或本質靜觀三途徑的具體工夫，盡心知性而知天。聖多瑪斯五路證證的宗旨正是在於使人人得以翦荊棘而由大路，撥雲霧而見青天。

　　　　　Human spirit is able to recognize the existence of God. Man needs to contemplate on "Where God is" before he recognizes it. The method of contemplating on "Where God is", for Thomas Aquinas is his proof of five ways. St. Thomas - five ways was firstly enlightened by Platos participation and contemplating on the Idea; Aristotle pointed out the life of contemplation is a life like God, contemplation is the most precious for human being among creatures, it is a intellectual virtue which leads human being to the happiness. The proof of Five Ways is secondly influenced by the Bible. The Book of Wisdom affirms: If they are capable of acquiring enough knowledge to be able to investigate the world, how have they been so slow to find its Master? In fact we could find the five ways' footprint in Thomas' commentary on the Gospel according to St. John chapter I which has mentioned about three kinds of contemplation. The third element is the influence of Dominican's contemplative spirituality: The path of affirmation and gradation. Lastly it comes from the genius of Thomas Aquians' summary. Looking from the development of Metaphysics, we could find that Thomas used the way of Analogy and the notion of participation. He sees beings take part in the perfection of Being, this makes beings be transcendental from the finite toward the infinite. Thomas strongly established his five ways passed through Neo-Platonism's Participation and Aristotle's Analogy, this includes the reason's use of the principles of potency and act, causality. Contemplation is the necessary way for understanding the proof of five ways, its practical methods for Thomas is through imaginary pictures, intelligible effects and contemplation in its essence. The aim of Thomas five ways is no doubt to lead human being pass through the wide way for visioning God.