approval of our interference be restricted to selections. It must be
extended to _additions_. Just as we can select factors from 'the given'
to construct 'reality,' we can add hypotheses to it to make it
'intelligible.' We can claim the right of causal analysis, and assume
that our dissections have laid bare the inner springs of the connection
of events. Moreover, to the 'real world which our choice has built out
of the chaos of 'appearances' we may hypothetically add 'infernal' and
'heavenly' regions.[B] Both are transformations of 'the given' by the
will, but, like the postulate of causal series, experience _may_ confirm
them. Kant's _a priori_ activity of the mind may thus in a sense supply
an answer to Hume--but only in a voluntaristic philosophy which would
probably have seemed too bold both to him and to Hume.



There can be no doubt that we do not approach the data of perception in
an attitude of quiescent resignation. Our desires and needs equip us
with assumptions and 'first principles,' which originate from within,
not from without. But how precisely should this mental contribution to
knowledge be conceived? In the last chapter of his _Psychology_ James
suggested that the mind's organization is essentially biological. It has
evolved according to sound Darwinian principles, and in so doing the
fittest of its 'variations' have survived. But were these variations
quite fortuitous? May they not have been purposive responses to the
stimulation of environment? Can logic have been invented like saws and
ships for purposes of human service? These are some of the stimulating
questions which James's work in _Psychology_ has suggested.

FOOTNOTES: