Such a method of evolution and growth is not possible in the vegetable
or animal kingdom, where _instinct_ is the only means for the
transmission of acquired knowledge. It is this feature that
differentiates man from all other created beings.

But here is a curious fact: In one realm of human experiences, in all
Christian civilized countries, it has been considered wrong, even in
some cases being counted a criminal offense, punishable by fine and
imprisonment, for anyone to make any record of, or transmit to
anyone else, any knowledge that may have been acquired regarding sex
relations in the human family.

To be sure, there has been preserved, from time to time, a body
of _professional_ knowledge of this sort, made and prepared by
physicians, but _confined strictly to that class of people_. No
attempt has been made to disseminate such knowledge among those who
most need it--the common people. On the contrary, every possible
effort is put forth to keep such knowledge from them. This is wholly
at variance with the practice regarding all other forms of human
knowledge, which is to spread, as widely as possible, all known data
that have so far been obtained.

There is not space, in this small volume, for pointing out the reasons
for this anomalous condition of affairs, but the chief cause of its
status, past and present, is grounded on two sources: The first of
these is a brutal selfishness which has come over to modern times from
a savage past; the second is a sort of pious prudery.

The result of these causes has been to make the whole subject of sex
in the human family, with its functions and mission in human affairs,