Shortly after the writing of Principia Mathematica was finished, and while the book was still printing, I was invited by Gilbert Murray to write a little book for The Home University Library setting out in popular terms a general outline of my philosophy. This invitation came at a fortunate moment. I was glad to escape from the rigours of symbolic deductive reasoning, and my opinions at that moment had a clear-cut definiteness which they did not have earlier or later and which made them easy to expound in a simple manner. The book had a great success and still sells widely. I think that most philosophers still regard it as an adequate exposition of my opinions.
Source: My Philosophical Development, Chapter 9 The External World
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