mendous difficulties in
expressing new thoughts and in indicating new methods. The reader who
stops to criticize words or expressions because of their more or less
happy or unhappy use will miss the whole point of the work. The reading of
it should be done with a view to seeing how much can be found in it of
what is new and good that may be elaborated further, and put into better
form. This new enterprise is too difficult and too vast for the unaided
labor of one man--life is too short.

The method used in this book in analysing life phenomena is essentially an
engineering method, and as physics and mechanics always suggest to
mathematicians new fields for analysis, it is not improbable that Human
Engineering will give mathematicians new and interesting fields for
research. The humblest role of mathematicians in Human Engineering may be
likened to that of "Public accountants" who put _in order_ the affairs of
business.

In relation to mathematics Bertrand Russell has said: "Logic is the youth
of mathematics, mathematics is the manhood of logic." This brilliant _mot_
of the eminent philosopher of mathematics is no doubt just and is
profoundly significant; the least it can teach us is that it is useless to
try to find a dividing line between logic and mathematics, for no such
line exists; to seek for one serves merely to betray one's ignorance of
mathematical philosophy. Elsewhere Mr. Russell says: "The hope of
satisfaction to our more human desires, the hope of demonstrating that the
world has this or that ethical characteristic, is not one which, so far as
I can see, philosophy can do anything whatever to satisfy." By
"philosophy" he means mathematical philosophy--a philosophy that is
rigorously scientific, not vaguely speculative. I am entirely unable to
agree with him that such a philosophy can make no contribution to ethics.
On the contrary, I contend, and in this book I hope to show, that by
mathematical philosophy, by rigorously scientific thinking, we can arrive
at the true conception of what a human being really is and that in thus
discovering the characteristic nature of man we come to the secret and
source of ethics. Ethics as a science will investigate and explain the
essential nature of man and the obligations which the essential nature of
man imposes upon human beings. It will be seen that to live righteously,
to live ethically, is to live in accordance with the laws of human nature;
and when it is clearly