The mirror. (Stillwater, Minn.) 1894-1925, 1901-06-27
MATHEW NAUTICAL
PHILOSOPHY.

N0 VI UuO mOoG upOIGouU
uses of mathematics is to be
~ found in the application of
the theory of probabilities to
the practical concerns of life; and it is
worth while to consider this thoroughly,
because it illustrates the nature of the
service rendered by the science in all
similar cases. That is, in all those
cases in which the assumptions lying
at the basis of the theory are derived
from experience, and not from defini-
tion. Let us consider briefly the
mathematical theory of probabilities
in it's application to insurance risks:
Human nature is curious mixture
of credulity and scepticism. The same
man who scorns method pretending
to predict future event will listen to
the agent of an enterprise which prom
ises the subscriber more than he SUBJ
scribes. His scepticism arises from
the fact that he does not know that the
theory of probabilities rests upon that
very experience which he boasts is the
guide of his own conduct, and his
credulity overlooks the fundamental
principle of all enterprises of the nature
of insurance: That, "some must pay
more than they receive in order that
others may receive more than they
pay"
The data on which weather pre-
dictions are founded is variable and
complex. Our knowledge of all the
factors in the problem of what the
weather will be tomorrow is so incom-
plete that the prediction is relatively
unreliable. On the other hand, while
we know practically nothing of the
causes which determine the sex of the
embryo, experience teaches us that the
proportion of males to females is al
most invariable, and nearly as twenty
one to twenty. That is, while nothing
can be more uncertain than the sex of
an unborn child, hardly any natural
phenomenon is more certain than that
in large district twenty-one males
will be born for every twenty females.
Notice also that in the two cases
above mentioned, the prediction is not
of the same kind. AS to the weather,
we attempt to predict single event.
the weather tomorrow; while in the
question of sex, our affirmation is not
of single event but of a series of
events.
The mean duration of life is another
example of knowledge founded on
wide observation. The uncertainty of
a single human life is proverbial.
Whereas, experience teaches us that
notwithstanding all the differences of
constitution, and the many accidents
to which human life is subject, the
average length of the lives Of large
number in the same community is so
very nearly the same that financial
risks depending upon it are classed
among legitimate business enterprises,
instead of among speculations.
Like illustrations are afforded by all
statistical inquiries. The number of
crimes of the same kind committed in
year, the ratio of convictions to
acquittals in jury trials, the number of
conflagrations, of ships lost in a par
ticular trade, ETC., all huctuate within
narrow limits, but all approach fixed
values as the range of observation is
more extended. A priori, we know
nothing of the probabilities of these
things very little of the causes which
determine the special event. We infer
from large experience that the wider
the experience, the safer the inference,
and our belief in the constancy Of the
operation of the laws of nature-laws
whose results we observe, although
perhaps ignorant of the laws them
selves. MAHNUD.