In doing so, our task will be to examine two principal elements:
one, the means on which we depend for interpreting the information
that is available; and the other, the source and character of the
information.

The means may be considered analogous to the navigator's
instruments, and is no less a thing than the brain or mental
machinery; and the information is simply the world about us as
seen in the existing things, such as machinery, methods, popular
notions, textbooks, etc., all of which may be classed as
environments, and may be considered as analogous to the charts and
other publications of our worthy example.

Like the mariner, we must determine the degree of reliability of
all these sources of information and our means for interpreting
observed facts.

When we have ascertained this we will know what allowance to make
from the "observed" to get the actual facts. With this knowledge
we will be able to accurately determine both our starting-point
and best course.

The importance of considering our own minds will be seen when we
realize that every new fact taken in must in a measure conform to
the previous ideas. If some of these old ideas are erroneous, the
mind must be more or less ready to discard them. It is very
difficult to dislodge deep-seated convictions. Contradictory ideas
are not assimilated. Only one of them is actually accepted. Even
when to the objective reasoning they seem false, they frequently