Page:Mysticism and Logic and Other Essays.djvu/249

 BY BERTRAND RUSSELL Human Knowledge Demy 8vo. Third Impression 305. net This book is intended for the general reader, not for professional philosophers. It begins with a brief survey of what science professes to know about the universe. In this survey the attempt is to be as far as possible impartial and impersonal; the aim is to come as near as our capacities permit to describing the world as it might appear to an observer of miraculous perceptive powers viewing it from without. In science, we are concerned with what we know rather than what we know. We attempt to use an order in our description which ignores, for the moment, the fact that we are part of the universe, and that any account which we can give of it depends upon its effects upon ourselves, and is to this extent inevitably anthropocentric. Bertrand Russell accordingly begins with the system of galaxies, and passes on, by stages, to our own galaxy, our own little solar system, our own tiny planet, the infinitesimal specks of life upon its surface, and finally as the climax of insignificance, the bodies and minds of those odd beings that imagine themselves the lords of creation and the end of the whole vast cosmos. But this survey, which seems to end in the pettiness of Man and all his concerns, is only one side of the truth. There is another side, which must be brought out by a survey of a different kind. In this second kind of survey, the question is no longer what the universe is, but how we come to know whatever we do know about it. In this survey Man again occupies the centre, as in the Ptolemaic astronomy. What we know of the world we know by means of events in our own lives, events which, but for the power of thought, would remain merely private. The book inquires what are our data, and what are the principles by means of which we make our inferences. The data from which these inferences proceed are private to ourselves; what we call &quot;seeing the sun&quot; is an event in the life of the seer, from which the astronomer s sun has to be inferred by a long and elaborate process, It is evident that, if the world were a higgledy-piggledy chaos, inferences of this kind would be impossible; but for casual inter-connectedness, what happens in one place would afford no indication of what has happened in another. It is the process from private sensation and thought to impersonal science that forms the chief topic of the book. The road is at times difficult, but until we have traversed it neither the scope nor the limitations of human knowledge can be adequately understood