what the destination is. To the minds of most people the desirable
outcome of human development would be a condition of society in
which all the inhabitants of the planet would enjoy a perfectly
happy existence. But it is impossible to be sure that civilisation
is moving in the right direction to realise this aim. Certain
features of our "progress" may be urged as presumptions in its
favour, but there are always offsets, and it has always been easy to
make out a case that, from the point of view of increasing
happiness, the tendencies of our progressive civilisation are far
from desirable. In short, it cannot be proved that the unknown
destination towards which man is advancing is desirable. The
movement may be Progress, or it may be in an undesirable direction
and therefore not Progress. This is a question of fact, and one
which is at present as insoluble as the question of personal
immortality. It is a problem which bears on the mystery of life.

Moreover, even if it is admitted to be probable that the course of
civilisation has so far been in a desirable direction, and such as
would lead to general felicity if the direction were followed far
enough, it cannot be proved that ultimate attainment depends
entirely on the human will. For the advance might at some point be
arrested by an insuperable wall. Take the particular case of
knowledge, as to which it is generally taken for granted that the
continuity of progress in the future depends altogether on the
continuity of human effort (assuming that human brains do not
degenerate). This assumption is based on a strictly limited
experience. Science has been advancing without interruption during
the last three or four hundred years; every new discovery has led to
new problems and new methods of solution, and opened up new fields
for exploration. Hitherto men of science have not been compelled to