ar, which was itself a gigantic industrial process,
another factor manifested itself and proved to be of the utmost
importance: namely, the human factor, which is not material but is mental,
moral, psychological. It has been found that maximum production may be
attained when and only when the production is carried on in conformity
with certain psychological laws, roughly determined by the analysis of
human nature.

Except for productive human labor, our globe is too small to support the
human population now upon it. Humanity must produce or perish.

Production is essentially a task for engineers; it essentially depends
upon the discovery and the application of natural laws, including the laws
of human nature. It is, therefore, not a task for old fashioned
philosophical speculation nor for barren metaphysical reasoning _in
vacuo_; it is a scientific task and involves the coordination and
cooperation of all the sciences. This is why it is an engineering task.

For engineering, rightly understood, is the coordinated sum-total of human
knowledge gathered through the ages, with mathematics as its chief
instrument and guide. Human Engineering will embody the theory and
practice--the science and art--of all engineering branches united by a
common aim--the understanding and welfare of mankind.

Here I want to make it very clear that mathematics is not what many people
think it is; it is not a system of mere formulas and theorems; but as
beautifully defined by Professor Cassius J. Keyser, in his book _The Human
Worth of Rigorous Thinking_ (Columbia University Press, 1916), mathematics
is the science of "Exact thought or rigorous thinking," and one of its
distinctive characteristics is "precision, sharpness, completeness of
definitions." This quality alone is sufficient to explain why people
generally do not like mathematics and why even some scientists bluntly
refuse to have anything to do with problems wherein mathematical reasoning
is involved. In the meantime, mathematical philosophy has very little, if
anything, to do with mere calculations or with numbers as such or with
formulas; it is a philosophy wherein precise, sharp and rigorous thinking
is essential. Those who deliberately refuse to think "rigorously"--that is
mathematically--in connections where such thinking is possible, commit the
sin of preferring the worse to the better; they deliberately violate the
supreme law of intellectual rectitude.

Here I have to mak