hout hunger, or drinking without thirst; then
would the system be but seldom out of working order. But so profound an
ignorance is there of the laws of life, that men do not even know that
their sensations are their natural guides, and (when not rendered morbid
by long--continued disobedience) their trustworthy guides. So that
though, to speak teleologically, Nature has provided efficient
safeguards to health, lack of knowledge makes them in a great measure
useless.

If any one doubts the importance of an acquaintance with the principles
of physiology, as a means to complete living, let him look around and
see how many men and women he can find in middle or later life who are
thoroughly well. Only occasionally do we meet with an example of
vigorous health continued to old age; hourly do we meet with examples of
acute disorder, chronic ailment, general debility, premature
decrepitude. Scarcely is there one to whom you put the question, who has
not, in the course of his life, brought upon himself illnesses which a
little information would have saved him from. Here is a case of
heart-disease consequent on a rheumatic fever that followed reckless
exposure. There is a case of eyes spoiled for life by over-study.
Yesterday the account was of one whose long-enduring lameness was
brought on by continuing, spite of the pain, to use a knee after it had
been slightly injured. And to-day we are told of another who has had to
lie by for years, because he did not know that the palpitation he
suffered under resulted from overtaxed brain. Now we hear of an
irremediable injury which followed some silly feat of strength; and,
again, of a constitution that has never recovered from the effects of
excessive work needlessly undertaken. While on every side we see the
perpetual minor ailments which accompany feebleness. Not to dwell on the
pain, the weariness, the gloom, the waste of time and money thus
entailed, only consider how greatly ill-health hinders the discharge of
all duties--makes business often impossible, and always more difficult;
produces an irritability fatal to the right management of children; puts
the functions of citizenship out of the question; and makes amusement a
bore. Is it not clear that the physical sins--partly our forefathers'
and partly our own--which produce this ill-health, deduct more from
complete living than anything else? and to a great extent make life a
failure and a burden instead of a benefaction and a p