Chapter XXXI: Section 2: Decline in Fertility Due to Some Natural Law

In the course of an inquiry on the fertility of women who had received a college education, the National Birth Rate Commission [63] attempted to discover to what extent birth control was practised amongst the middle and professional classes. Of those amongst whom the inquiry was made 477 gave definite answers, from which it was ascertained that 289, or 60 per cent., consciously limited their families, or attempted to do so; and that 188, or 40 per cent. made no attempt to limit their families. Amongst those who limited their families 183 stated the means employed, and of these, 105, or 57 per cent., practised continence, whilst 78, or 43 per cent., used artificial or unnatural methods.

Now comes a most extraordinary fact. Dr. Major Greenwood, [64] a statistician whose methods are beyond question, discovered that there was no real mathematical difference between the number of children in the "limited" families and the number in the unlimited families. In both groups of families the number of children was smaller than the average family in the general population, and in both groups there were fewer children than in the families of the preceding generation to which the parents belonged. Dr. Greenwood states that this is _prima facie_ evidence that deliberate birth control has produced little effect, and that the lowered fertility is the expression of a natural change. Nevertheless, he holds that the latter explanation cannot be accepted as wholly proved on the evidence, owing to certain defects in the data on which his calculations were based.

"I am of opinion that we should hesitate before adopting that
interpretation in view of the cogent indirect evidence afforded by
other data that the fall of the birth-rate is differential, and that
the differentiation is largely economic. There are at least two
considerations which must be borne in mind in connection with these
schedules. The first is, that all the marriages described as unlimited
may not have been so. I do not suggest that the answers are
intentionally false, but it is possible that many may have considered
that limitation implied the use of mechanical means; that marriages in
which the parties merely abstained from, _or limited the occasions of_,
sexual intercourse may have frequently entered as of unrestricted
fertility."

The above italics are mine, because, if that surmise be correct, it goes to prove that the restriction of intercourse to certain periods, which restriction the married may lawfully practise, is as efficacious in limiting the size of a family as are those artificial methods of birth control contrary both to natural and to Christian morality. Dr. Major Greenwood continues as follows:

"In the second place, the schedules do not provide us with information
as to when limitation was introduced. We are told, for instance, that
the size of the family was five and that its number was limited. This
may mean _either_ that throughout the duration of the marriage
preventive measures were adopted from time to time, _or_ that _after_
five children had been born fertile intercourse was stopped. In the
absence of detailed information on this point it is plainly impossible
to form an accurate judgment as to the effect of limitation."

There are, therefore, no accurate figures to indicate the extent to which birth control has contributed to the decline in the birth-rate.