In the following pages I have confined myself in the main to those prob-
lems of philosophy in regard to which I thought it possible to say
something positive and constructive, since merely negative criticism
seemed out of place. For this reason, theory of knowledge occupies a lar-
ger space than metaphysics in the present volume, and some topics
much discussed by philosophers are treated very briefly, if at all.
I have derived valuable assistance from unpublished writings of G. E.
Moore and J. M. Keynes: from the former, as regards the relations of
sense-data to physical objects, and from the latter as regards probability
and induction. I have also profited greatly by the criticisms and sugges-
tions of Professor Gilbert Murray.
