本文主要是藉由速度的概念來重新理解幾位重要思想家的思想，論證速度概念乃是他們省思現代科技及媒介的核心概念，進而指出速度概念是掌握當今社會文化特性的關鍵之一。而為了凸顯速度概念的重要性，本文從Heidegger有關科技與人類之間的存有論著作入手，取徑McLuhan關於傳播媒介對社會文化影響之相關論述、Stiegler有關技術、速度與時間之間關餘的討論，以及Virilio對即時性電子媒介的速度學分析，逐步證成本文的主張。進而延伸Heidegger的技術存有論，提出速度存有論的概念，凸顯速度與人類之間乃是一種涉及人類身體與存有本質的風險關條。換言之，人類的本質乃是由工其、科技的使用所界定，而追求速度又做為科技進展的重心，但缺乏自覺的加速卻也蘊含著失控的可能性，尤其即時性電子媒介的發展更可能危及人類的存有本質。更清楚地說，人類對科技的控制能力永遠是落後於科技的進展，而正如Stiegler與Virilio所指出的，在即時性電子媒介所主導的當代，此一時間 落差在即時性(realtime)壓縮真實空間(real space)、促成 全球化趨勢的同時，不僅風險的規模更為擴大，也可能更為迅速，乃至於風險的內涵亦更深刻地指向人類的存有本質，從而危及人類做為人類的根本。

With the concept of speed， this paper intends to refresh our understanding of the thought of certain thinkers in order to reflect on the characteristic of modem society. Starting from Heidegger's ontology of technology， the author tries to reinterpret the media theory of McLuhan， Stiegler's book on technics， speed， and time， and Virilio's dromology to illuminate that the relationships between human beings and speed is one of ontological one with its risk regarding the essence of human nature. However， with the advance of modernization and the acceleration of technology and media to the instantaneity of real-time， our ability to control this development always lags further behind the immediate happening of the risk and the speedy change of technology and our social， cultural milieu. In order not to lose control of this process of speed-up， it is necessary for us to elaborate the conceptual and theoretical contents of ontology of velocity to capture the mechanism of this transformation.