here, in fact, that the
consequences are most weighty and far-reaching. We shall need to refer
to them again in detail. But to simplify my explanation, I will here
choose another example: that of inert matter, of the perception on which
the physical is based. It is in this case that the divergence between
common perception and pure perception, however real it may be, assumes
least proportions.

Therefore it appears most in place in the sketch I desire to trace of an
exceedingly complex work, where I can only hope, evidently, to indicate
the main lines and general direction.

We readily believe that when we cast our eyes upon surrounding objects,
we enter into them unresistingly and apprehend them all at once in their
intrinsic nature. Perception would thus be nothing but simple passive
registration. But nothing could be more untrue, if we are speaking of
the perception which we employ without profound criticism in the
course of our daily life. What we here take to be pure fact is, on
the contrary, the last term in a highly complicated series of mental
operations. And this term contains as much of us as of things.

In fact, all concrete perception comes up for analysis as an
indissoluble mixture of construction and fact, in which the fact is only
revealed through the construction, and takes on its complexion. We all
know by experience how incapable the uneducated person is of explaining
the simple appearance of the least fact, without embodying a crowd of
false interpretations. We know to a less extent, but it is also true,
that the most enlightened and adroit person proceeds in just the same
manner: his interpretation is better, but it is still interpretation.

That is why accurate observation is so difficult; we see or we do not
see, we notice such and such an aspect, we read this or that, according
to our state of consciousness at the time, according to the direction of
the investigation on which we are engaged.

Who was it defined art as nature seen through a mind? Perception, too,
is an art.

This art has its processes, its conventions, and its tools. Go into a
laboratory and study one of those complex instruments which make our
senses finer or more powerful; each of them is literally a sheaf of
materialised theories, and by means of it all acquired science is
brought to bear on each new observation of the student. In exactly the
same way our organs of sense are actual instruments constructed by the
unconsci