Nor is this all. Life, besides being thus immensely deteriorated, is
also cut short. It is not true, as we commonly suppose, that after a
disorder or disease from which we have recovered, we are as before. No
disturbance of the normal course of the functions can pass away and
leave things exactly as they were. A permanent damage is done--not
immediately appreciable, it may be, but still there; and along with
other such items which Nature in her strict account-keeping never drops,
it will tell against us to the inevitable shortening of our days.
Through the accumulation of small injuries it is that constitutions are
commonly undermined, and break down, long before their time. And if we
call to mind how far the average duration of life falls below the
possible duration, we see how immense is the loss. When, to the numerous
partial deductions which bad health entails, we add this great final
deduction, it results that ordinarily one-half of life is thrown away.

Hence, knowledge which subserves direct self-preservation by preventing
this loss of health, is of primary importance. We do not contend that
possession of such knowledge would by any means wholly remedy the evil.
It is clear that in our present phase of civilisation, men's necessities
often compel them to transgress. And it is further clear that, even in
the absence of such compulsion, their inclinations would frequently lead
them, spite of their convictions, to sacrifice future good to present
gratification. But we _do_ contend that the right knowledge impressed in
the right way would effect much; and we further contend that as the laws
of health must be recognised before they can be fully conformed to, the
imparting of such knowledge must precede a more rational living--come
when that may. We infer that as vigorous health and its accompanying
high spirits are larger elements of happiness than any other things
whatever, the teaching how to maintain them is a teaching that yields in
moment to no other whatever. And therefore we assert that such a course