o answers to this problem: periodic
housecleaning, without fear or favor, together with careful scrutiny of
the apprentices and other newcomers in the field.

Every social group has its quota of defectives and
delinquents--biological and social, physical, mental, emotional. Here
the critical problem is where to draw the line. Perhaps the best general
answer is to measure productiveness, including those who make a net
contribution, including those whose presence is desirable and excluding
undesirables. Again this involves periodic housecleanings.

Throughout the past two centuries mankind has been confronted by an
epoch-making, many sided development--the great revolution of
1750-1970. As I write, the great revolution is modifying the structure
and functioning of human society and, consequently, the forces which
condition, shape and, in large measure, determine the directions and
channels in which humanity lives, moves and has its being.

The great revolution is changing man's relation to nature, to the
structure and function of human society and the ways in which men think,
feel, act and live. The great revolution has shifted the human living
place from rural to urban, replaced a large measure of self-employment
by wagery, lifted large segments of mankind out of scarcity into
abundance, led to widespread migrations across Europe and from continent
to continent, expanded nations and built empires. In the course of these
developments Europe became the center of world economic, political and
cultural affairs, held the position briefly and lost it in the course of
two general, suicidal wars.

Speaking broadly, such a period in the life of any society may be
described as a revolutionary situation--one in which changes are made
frequently, rapidly and with far reaching consequences. In a word, the
existing social pattern is in process of being turned over, turned
upside down, transformed by forces which seem to operate according to
their own principles and often quite independently of human intention or
intervention.

Our society--western civilization--is undergoing a revolution. People
born into a rapidly changing society are often tempted and sometimes
compelled to play significant roles in the revolutionary process.
Unconsciously or consciously, unwilling and unwitting or deliberately
and purposefully they are revolutionaries.

Among the participants in the revolutionary process, the far-seeing,
imaginative, percept