Whatever happened to some men in the past affects virtually all men today. This was not always true. In short, all history is catching up with us, and this very difference, paradoxically, underscores our break with the past. Thus the scope of change is fundamentally altered. Across space and through time, change has a power and reach in this, the 800th lifetime, that it never did before.

But the final, qualitative difference between this and all previous lifetimes is the one most easily overlooked. For we have not merely extended the scope and scale of change, we have radically altered its pace. We have in our time released a totally new social force – a stream of change so accelerated that it influences our sense of time, revolutionizes the tempo of daily life, and affects the very way we "feel" the world around us. We no longer "feel" life as men did in the past. And this is the ultimate difference, the distinction that separates the truly contemporary man from all others. For this acceleration lies behind the impermanence – the transience – that penetrates and tinctures our consciousness, radically affecting the way we relate to other people, to things, to the entire universe of ideas, art and values.

To understand what is happening to us as we move into the age of super-industrialism, we must analyze the processes of acceleration and confront the concept of transience. If acceleration is a new social force, transience is its psychological counterpart, and without an understanding of the role it plays in contemporary human behavior, all our theories of personality, all our psychology, must remain pre-modern. Psychology without the concept of transience cannot take account of precisely those phenomena that are peculiarly contemporary.