This quote by the artist Paul Klee summarizes the thesis of this book which is a simple if not unoriginal one: that cybernetic techno-culture is in the busy process of fundamentally changing our human perceptions of self, society, and reality. And for that reason the book is a thought-provoking read even if on all points it is not entirely convincing.
The author speaks of three intervals that have shaped man's cognitive history. The first interval is TIME, the way in which its daily, seasonal, and annual cycles have shaped our sense of human identity as a time-bound being. The second interval is SPACE, and this refers to our habit of locating (and thus measuring) ourselves in terms of what amounts to geographic relativism; the key idea here is distance and its historical role in the way that we conceive of ourselves and design reality.
Now the third interval is SPACE-TIME, that is, the way the speed of light serves as the technological and increasingly practical standard for "the perception of duration and of the world's expanse as phenomena" (p. 13), also referred to in the text as 'time-light'. What we now casually accept as the 'real-time' occurrence of events is a reflection of how instantaneous telecommunications have (1) dissolved time's traditional flow of past, present, and future, (2) eliminated distance and any physically-defining sense of horizon, and (3) allowed a world defined in terms of continuous 'telepresence' to emerge. This means that, ironically, the age-old religious and philosophical ideal of living in the present, for the moment, in the now, etc. will only now be realized in fact and EN MASSE by means of our burgeoning communications technologies and the forms of perceptual servitude accompanying them.
Virilio mentions in passing the possible anthropological impact of these developments in areas such as politics, social life, economics, and sexuality, and these will strike the reader as insightful, alarmist, or prematurely ridiculous depending upon his own attitudes about these matters, but there is no denying the assertion that we are currently in the process of having some very ancient and fundamentally formative ways of reckoning human reality forever changed and not necessarily for the sake of a brighter tomorrow that, by Virilio's estimation, the techno-bondage of the 'telepresent' prevents.