The eleventh impression of a collection of essays, 

 some of which were included in an early volume, 

 now out of print, entitled Philosophical Essays. 

 The author describes the first five of these as 

 "entirely popular" and these include some 

 well-known titles: Mysticism and Logic, The 

 Place of Science in a Liberal Education, A Free 

 Man's Worship, The Study of Mathematics, 

 Mathematics and the Metaphysicians. The essays 

 that follow are, he says, "somewhat more tech- 

 nical": On Scientific Method in Philosophy, The 

 Ultimate Constituents of Matter, The Relation 

 of Sense- Data to Physics, On the Notion of Cause, 

 Knowledge by Acquaintance and Knowledge by 

 Description. 



ELEVENTH IMPRESSION 



Mysticism & Logic 



B. Russell 



George Allen & Unwin 



