The student's knowledge is more useful to the builder, and I do not wish to
claim that we should ever neglect it; but the only true knowledge is that
of the engineer. And what I have just said does not concern material
objects only. Who has absolute knowledge of religion, he who analyses it
in psychology, sociology, history, and metaphysics, or he who, from within,
by a living experience, participates in its essence and holds communion
with its duration?

But the external nature of the knowledge obtained by conceptual analysis is
only its least fault. There are others still more serious.

If concepts actually express what is common, general, unspecific, what
should make us feel the need of recasting them when we apply them to a new
object?

Does not their ground, their utility, and their interest exactly consist in
sparing us this labour?

We regard them as elaborated once for all. They are building-material,
ready-hewn blocks, which we have only to bring together. They are atoms,
simple elements--a mathematician would say prime factors--capable of
associating with infinity, but without undergoing any inner modification in
contact with it. They admit linkage; they can be attached externally, but
they leave the aggregate as they went into it.

Juxtaposition and arrangement are the geometrical operations which typify
the work of knowledge in such a case; or else we must fall back on
metaphors from some mental chemistry, such as proportioning and
combination.