because it is the effect of the optic raj. By keeping 1 strictly 
to this use of the word, we maintain a very decided advantage 
m such an inquiry as the present. 
This moral sense has features that constrain us to class it 
with the other senses. For example, it is affected by ideas of 
right and wrong ‘ so is the sense of hearing by harmony and 
discord ; so are all the senses by that which distresses, as well 
as by that which pleases. This sense, too, is useful to man, 
as other senses are to their possessors. Like the feelers of an 
insect or reptile, or the wings of a bat, by their delicate sensi- 
bility of touch, enabling their possessors to find their way, so 
does the keenly sensitive moral susceptibility enable its pos- 
sessor to find the right path in action when his intelligence 
as to that path is defective in a high degree. As the affections 
of other senses constrain by the pleasure they give, or the 
pain they inflict, so does this moral sense in man. Hence 
it seems to me most important that it should be recognised 
and cultivated, just as sight or any other sense, and even more 
fully and carefully than all the rest put together. 
The true moral sensation is clearly and easily distinguishable 
from all affections of the lower animals. It is utterly different 
from the effect of approbation or its opposite, and also from 
that of promised reward, or threatened punishment. Many of 
the lower animals are susceptible of these effects, and very 
keenly so. A dog, for example, is made to cower, and even 
to run off and hide itself, when spoken to as having acted 
wrongly ; and it shows signs of unquestionable gratification 
when praised, as for a useful or noble action. This is more 
readily mistaken for the action of a moral sense than the effect 
of threats or. promises of reward. But it is to be observed 
that the dog is equally affected by the praise or blame, what- 
ever be the right or wrong in the case. That simply shows 
that he has neither the moral idea nor the capacity of feeling 
m accordance with it. The moral sense is as distinct from the 
susceptibility of praise and blame as hearing is from tasting, 
or from any other sense. 3 
In saying this, we do not deny thought to the animal. That 
m which one sensation is distinguished from another, so as to 
make objects of a material nature affect what may be called 
the lower mind, as objects , must be of the nature of thought,— 
must, in fact, be reasoning. So far as there is evidence of this 
in the lower, creatures, it is unwise to deny it. But so is it 
unwise to mistake such thought and reasoning, and the feelino- 
which results from it, for that thought in which true moral 
distinctions are perceived, and the moral sense made evident. 
Where there is no blame from others, nor the slightest idea 
