932 PHILOSOPHY OF ZOOLOGY. 
mals, in general, seem to have a tolerably correct notion of 
their own powers, as we do not often see them attempting 
to accomplish objects for which their strength is inadequate. 
Thus, we have seen a pointer which, if a hare was wound- 
ed, would pursue with the utmost keenness, but if other- 
wise, would witness her escape without exertion. It is the 
knowledge of the variety of power which sometimes makes 
a horse run away with a bad rider, when he would not eyen 
make the attempt with a good one. 
4. Truth.—Though many have endeavoured to give a 
satisfactory answer to the question, “ What is Truth ?” 
few have succeeded in the attempt. The failure, we ap- 
prehend, has in a great measure arisen from the variety of 
meanings attached to the term, and the impossibillity of 
giving a definition which shall include the whole, indepen- 
dent altogether of our limited acquirements. Thus, truth 
is by some considered as opposed to talsehood, by others 
to ignorance, and by many to duty. At present, we shall 
consider J'ruth as expressing the actual existence of things. 
Our knowledge derived from the impressions made on the 
senses, and from reflection, or experience, is to every one 
the standard by which he judges of truth. In consequence 
of the origin of this idea of reflection, a thing may be true, 
which, from experience, we cannot affirm; or false, which 
we cannot deny. 
In the acquisition of truth, we are aided by Experience 
and Testimony. 
(a.) Hxperience.—The value of the information furnish- 
ed by experience, must necessarily depend on the success- 
ful employment of the various instruments of our percep- 
tion and powers of reflection. Man appears to attend to 
the exercise of those powers with greater intensity, and to 
vary and repeat the operations which they perform more fre- 
