reconstruction which the hypothesis offers, it is possible for
scientific conduct to proceed.

But if the universal character of the hypothesis and the tested theory
belong to the instrumental character of thought in so reconstructing a
world that has proved to be imperfect, and inadequate to conduct, the
stuff of the world and of the new hypothesis are the same. At least this
is true for the scientist who has no interest in an epistemological
problem that does not affect his scientific undertakings in one way nor
another. I have already pointed out that from the standpoint of logical
and psychological analysis the things with which science deals can be
neither ultimate elements nor sense-data; but that they must be phases
and characters and parts of things in some whole, parts which can only
be isolated because of the conflict between an accepted meaning and some
experience. I have pointed out that an analysis is guided by the
practical demands of a solution of this conflict; that even that which
is individual in its most unique sense in the conflict and in attempts
at its solution does not enter into the field of psychology--which has
its own problems peculiar to its science. Certain psychological problems
belong to the problems of other sciences, as, for example, that of the
personal equation belongs to astronomy or that of color vision to the
theory of light. But they bulk small in these sciences. It cannot be
successfully maintained that a scientific observation of the most unique
sort, one which is accepted for the time being simply as a happening in
this or that scientist's experience, is as such a psychological datum,
for the data in psychological text-books have reference to
_psychological_ problems. Psychology deals with the consciousness of the
individual in its dependence upon the physiological organism and upon
those contents which detach themselves from the objects outside the
individual and which are identified with his inner experience. It deals
with the laws and processes and structures of this consciousness in all
its experiences, not with _exceptional_ experiences. It is necessary to
emphasize again that for science these particular experiences arise
within a world which is in its logical structure organized and
universal. They arise only through the conflict of the individual's
experience with such an accepted structure. For science individual
experience _presupposes_ the organized structure; hence it