The Republican. [volume] (Oakland, Md.) 1877-current, 1908-05-21
MENTAL FERTILITY.
The Error of hasty Estimate Fully
Shown.

.
ton about three years ago that
mans usefulness is limited by the
age Of forty it was received with
widespread skepticism. 1t was
possible in a few minutes for any
well informed person to bring to
mind so many exceptions to what
was here laid down as a rule
among distinguished poets, artists,
scientists, statesmen and philoso-
pliers that the statement seemed
to have been made without due
reflection, if not to be absolutely
unwarranted. Doubts as to its
accuracy, possibly combined with
other motives, impelled DR.. W.
A. Newman DOrland to undertake
an inquiry, the results of which
were presented in The Century
Magazine" for April. An appeal
is made to history to substantiate
or d1sprove the theory referred to.
The biographies of no fewer than
four hundred Of the worlds chief
workers and thinkers have been
consulted for light on the subject.
Such a method admits of a trust
worthy statistical reply to Dr..
Osler. In adopting it DR.. Dor
land has performed a valuable bit
of service.
1t was found to be necessary at
the outside to discriminate be-
tween men of action and men of
thought, between those in which
the emotional nature was transcen-
dent and those in whom a pro.
found mentality was the great
characteristic. The former quality
usually manifests itself, Dr.. Dor
land shows, sooner than the latter.
Hence, the age at which one
class of genius is manifest Is often
earlier than that of another. 1t
appears from Dr.. Dorland's figures
that the famous musical composers
began their important work at the
average age of seventeen, while
that of satirists and eminent
humorists was delayed until
thirty-two. The average age for
all classes included in his compre-
hensive survey is twenty four, and
this represents pretty fairly the
commencement of real achieve
ment by chemists, physicians and
inventors. Actors and warriors
distinguish themselves at an earli-
er age, and mathematician, phi
losophers and reformers generally
attain a ripper one before making
their mark.
To say exactly when a great
mans career eliminates, or, in
other words, to select his most
precious contribution to Civiliza-
ton, is extremely difficult in
many cases. An opinion of this
sort often demands a critical iudg-
ment of rare excellence, and it
might not go unChallenged. The
estimate which one generation
placed on a given deed, moreover,
might differ from that of the next.
Nevertheless, DR.. Dorland has un-
| dertaken to perform the task, and
is led to conclude that for the per
Torrance OF their master work the
average age of the four hundred
men included in his study is fifty.
Here, as in the beginning of their
careers, rather wide range is OBJ
servable. The average for chem
lists and physicians, for instance.
is forty-one; for poets and inyen-
tors, forty-four; for physicians and
surgeons, ffty-two; for philoso-
pliers, fifty-four, and for naturalists
and jurists, fifty eight.
Obviously mans usefulness is
liable to continue for a sensible
period after his most valuable
service has been rendered. What
seems to be the most instructive
deduction from DR.. DOrland' S
figures is that the average duration
of marked mental fertility Is forty
years. If, then. the age Of
twenty -four be taken as the mean
starting point, productiveness
! MIGHT reasonably he exneCted to