As you say, the way string theory requires all these extra dimensions and this comes from certain consistency requirements about how string should behave and so on.

In the book, I make the point that here we have string theory and here we have twistor theory and we don't know if either one of them is the right approach to nature.

Well, gauge theory is very fundamental to our understanding of physical forces these days. But they are also dependent on a mathematical idea, which has been around for longer than gauge theory has.

The basic theory in twistor theory is not to add extra dimensions.

Theory is splendid but until put into practice, it is valueless.

But the fact a person denies that he is theorising is no reason for taking him at his word and failing to investigate what implicit theory is involved in his statements.

But the scientific importance of a change in knowledge of fact consists precisely in j its having consequences for a system of theory.

It is probably safe to say that all the changes of factual knowledge which have led to the relativity theory, resulting in a very great theoretical development, are completely trivial from any point of view except their relevance to the structure of a theoretical system.

In so far as such a theory is empirically correct it will also tell us what empirical facts it should be possible to observe in a given set of circumstances.

The implications of these considerations justify the statement that all empirically verifiable knowledge even the commonsense knowledge of everyday life - involves implicitly, if not explicitly, systematic theory in this sense.

Theory not only formulates what we know but also tells us what we want to know, that is, the questions to which an answer is needed.

In a certain sense, aspects of my solo playing were developed in order to test the theory about how long particular elements could be, as parts of so-called free improvisations.

In the first quarter of the nineteenth century the experimental proof for the interdependence of the composition and properties of chemical compounds resulted in the theory that they are mutually related, so that like composition governs like properties, and conversely.

The situation of the Old Left was the theory of Socialist Realism, etc. It seemed pointless to argue. We stayed carefully away from people who wrote for the New Masses.

That is why one day I said my game will be like the Pythagorean Theorem - hard to figure out. A lot of people really don't know the Pythagorean Theory. They don't make them like me anymore. They don't want to make them like that anymore.