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 gener- 
ally, 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 standard- 
of-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