a foundation—leading to the notion that general observations about living systems should normally be analyzed on the basis of evolutionary history rather than abstract theories. And part of the reason for this is that traditional mathematical models have never seemed to come even close to capturing the kind of complexity we see in biology. But the discoveries in this book show that simple programs can produce a high level of complexity. And in fact it turns out that such programs can reproduce many features of biological organisms—and for example seem to capture some of the essential mechanisms through which genetic programs manage to generate the actual biological forms we see. So this means that it becomes possible to make a wide range of new models for biological systems—and potentially to see how to emulate the essence of their operation, say for medical purposes. And insofar as there are general principles for simple programs, these principles should also apply to biological organisms—making it possible to imagine constructing new kinds of general abstract theories in biology.

Social Sciences. From economics to psychology there has been a widespread if controversial assumption—no doubt from the success of the physical sciences—that solid theories must always be formulated in terms of numbers, equations and traditional mathematics. But I suspect that one will often have a much better chance of capturing fundamental mechanisms for phenomena in the social sciences by using instead the new kind of science that I develop in this book based on simple programs. No doubt there will quite quickly be all sorts of claims about applications of my ideas to the social sciences. And indeed the new intuition that emerges from this book may well almost immediately explain phenomena that have in the past seemed quite mysterious. But the very results of the book show that there will inevitably be fundamental limits to the application of scientific methods. There will be new questions formulated, but it will take time before it becomes clear when general theories are possible, and when one must instead inevitably rely on the details of judgement for specific cases.