70 THE SHADOW OF THE WORLD’S FUTURE
quite appropriate to indicate any particular number as
an actual limiting value: such a value is not unique
but is dependent.
Prof. E. M. East has given 5200 millions as his
estimate of the limit. His cogent reasons for this
figure have been set out in his work, Mankind at the
Crossroads, already mentioned. These reasons are
manifestly based very largely upon the assumption of
a status not differing fundamentally from the existing
character of our civilisation. Subject to this, it will
no doubt command a high degree of assent with anyone
who weighs what has been submitted in the work in
question. From a review of the whole situation, and
taking account of probable advances in the technique
of agriculture and in industrial processes generally,
 the limit may, perhaps, be set somewhat
higher, perhaps even as high as 35 per cent. more,
say 7020 millions. With a lowering of the standardof-living
 it may be made higher yet; and again
still higher if all migration difficulties could be
completely eliminated. The following numbers are
suggested as likely to be possible in the several cases
indicated in connection with them, viz.: Prof. East’s
estimate 5200 millions; allowing for the extension of
agricultural areas and some advance in agricultural
and general industrial technique, say- 7020; allowing
for scientific advances more fully—this, of course, is
somewhat conjectural—say ooo; and finally allowing
for the freest possible migration and the appropriate
co-ordination of all human effort, with the complete
elimination of the jeopardy of war, so that all effort
could be directed to the maintenance of human beings,
say 11,000 millions. These numbers are, of course,
subject to a considerable measure of uncertainty.
This last estimate is equivalent to each human being
occupying on the average only about 3-0 acres, and
this area has to provide for his forests and his share in