6. This brings us to the last, and historically the most fertile, of the
sources of Pragmatism, Psychology. The publication in 1890 of James's
great _Principles of Psychology_ opened a new era in the history of that
science. More than that, it was destined in the long run to work a
transformation in philosophy as a whole, by introducing into it those
biological and voluntaristic principles to which he afterwards applied
the generic name of Pragmatism, or philosophy of action. We must pass,
then, to consider the New Psychology of William James.




CHAPTER II


THE NEW PSYCHOLOGY

Until the year 1890, when James's _Principles_ were published, the
psychology of Hume reigned absolutely in philosophy.[A] All empiricists
accepted it enthusiastically, as the sum of philosophic wisdom; all
apriorists submitted to it, even in supplementing and modifying it by
'transcendental' and metaphysical additions; in either case it remained
uncontested _as psychology_, and, by propounding an utterly erroneous
analysis of the mind and its experience, entangled philosophy in
inextricable difficulties.



Hume had, as philosophers commonly do, set out from the practically
sufficient analysis of experience which all find ready-made in language.