FUNCTION OF CRITICISM IN ADVANCEMENT OF SCIENCE. 343 
did power of hierarchy pertains to the Newtonian law of 
gravitation, to the mechanical equivalent of heat, to entropy, 
to potential and kinetic energy, to the principle of conserva¬ 
tion of work energy, to chemical equivalents, to the electric 
and magnetic cross-connections. If the extension of the ele¬ 
ments of knowledge threatens to overwhelm our powers of 
endurance, we may take refuge in the belief that the pro¬ 
foundly mysterious power of the mind, by which unification 
in laws of deeper intensity is going on pari passu, will be 
ultimately able to keep the scales of judgment and criticism 
evenly poised in a just equilibrium. 
It is evident that the memory of the multitude of incidents 
which have occurred tempts one to relate many stories of 
faulty criticism, and thus to draw aside from the real object 
of this address, namety, to give a few examples of the sound 
criticism which has materially contributed to the advance¬ 
ment of science. However, before passing on to that part of 
the subject, one may be permitted to illustrate the erroneous 
use of the three principles which have been laid down for 
the guidance of critical efforts. Nothing is more common 
than for a critic to be wrong about his own comprehension 
of the facts in the case, and this may be partly due to a lack 
of complete information or to a tendency to jump to conclu¬ 
sions without sufficient preliminary study. 
1. A traveler on the western arid plains found some hard 
balls lying on the ground about the size of a goose egg and 
coated with a white shell which contained a mass of tough 
grass, hair, and other loose material. Specimens were duly 
sent east for expert opinion as to their nature, with an ac¬ 
count of the conditions under which they were discovered. 
The answer was returned that these balls were buffalo cuds 
which had become hardened by exposure. Nevertheless the 
same traveler afterwards saw some bugs—tumble-bugs he 
called them—who industriously formed little balls on the 
ground and then rolled them along till they had grown be¬ 
yond their strength to move, having by that time acquired 
considerable size, when they were abandoned. So the balls 
never performed in the function of buffalo digestion. 
