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HERMANN VON HELMHOLTZ
to the conditions in which it is placed, arrives at its goal
along the shortest path, in the shortest time, and with the
least effort. This phenomenon has been regarded as the result
of a designed wisdom: its general statement in the region of
pure mechanics is known as the Principle of least Action. Το
trace the phenomenon in its application to all forces, through
the whole of nature, is the problem to which Helmholtz has
devoted a part of the last decade. As yet the significance of
these researches is not thoroughly understood. An investigator
of this stamp treads a lonely path: years pass before even a
single disciple is able to follow in his steps.
It would be futile to try to enter into particulars of all
Helmholtz's researches. Our omissions might be divided
amongst several scientific men and would amply suffice to
make all of them famous. If one of them had carried out
Helmholtz's electrical researches and nothing else, we should
regard him as our chief authority on electricity. If another
had done nothing but discover the laws of vortex-motion in
fluids, he could boast of having made one of the most beautiful
discoveries in mechanics. If a third had only produced the
speculations on the conceivable and the actual properties of
space, no one would deny that he possessed a talent for pro-
found mathematical thought. But we rejoice to find these
discoveries united in one man instead of divided amongst
several. The thought that one or other of them might be a
mere lucky find is rendered impossible by this very union: we
recognise them as proofs of an intellectual power far exceeding
our own, and are lost in admiration.
And yet these actual performances give but an inadequate
idea of his whole personality. How can we estimate the
intellectual value of the inspiration which he imparted, at first
to his contemporaries, and afterwards to the pupils who flocked
to him from far and near? It is true that Helmholtz never
had the reputation of being a brilliant university teacher, as
far as this depends upon communicating elementary facts to the
beginners who usually fill the lecture-rooms. But it is quite
another matter when we come to consider his influence upon
trained students and his pre-eminent fitness for guiding them in
original research. Such guidance can only be given by one who
is himself a master in it, and its value is measured by his own