simple programs do than in all the previous ten years put together. My earlier work had shown me the beginnings of some unexpected and very remarkable phenomena. But now from my new experiments I began to see the full force and generality of these phenomena.

As my methodology and intuition improved, the pace of my discoveries increased still more, and within just a couple of years I had managed to take my explorations of the world of simple programs to the point where the sheer volume of factual information I had accumulated would be the envy of many long-established fields of science.

Quite early in the process I had begun to formulate several rather general principles. And the further I went, the more these principles were confirmed, and the more I realized just how strong and general they were.

When I first started at the beginning of the 1980s, my goal was mostly just to understand the phenomenon of complexity. But by the mid-1990s I had built up a whole intellectual structure that was capable of much more, and that in fact provided the foundations for what could only be considered a fundamentally new kind of science.

It was for me a most exciting time. For everywhere I turned there were huge untouched new areas that I was able to explore for the first time. Each had its own particular features. But with the overall framework I had developed I was gradually able to answer essentially all of what seemed to be the most obvious questions that I had raised.

At first I was mostly concerned with new questions that had never been particularly central to any existing areas of science. But gradually I realized that the new kind of science I was building should also provide a fundamentally new way to address basic issues in existing areas.

So around 1994 I began systematically investigating each of the various major traditional areas of science. I had long been interested in fundamental questions in many of these areas. But usually I had tended to believe most of the conventional wisdom about them. Yet when I began to study them in the context of my new kind of science I kept on seeing signs that large parts of this conventional wisdom could not be correct.

The typical issue was that there was some core problem that traditional methods or intuition had never successfully been able to address—and which the field had somehow grown to avoid. Yet over