INTRODUCTION. I 
vii 
Those cats and dogs that are taken from a state of 
natural wildness in the fores t, transmit their fierce- 
ness to their young ; and, however concealed in 
general, it breaks out upon several occasions. 
Tims’] the assiduity and application of man in 
bringing them up, not only alters their disposition, 
but their very forms ; and the difference between 
animals in a state of nature and domestic tameness, 
is so considerable, that M. Suffon has taken this as 
a principal distinction in classing them. 
In taking a cursory view of the form of quadru- 
peds we may easily perceive that, of all the ranks 
of animated nature, they bear the nearest resem- 
blance to man. This similitude will be found 
more striking when erecting themselves on their 
hinder feet, they are taught to walk forward in an 
upright posture. We then see that all their ex- 
tremities in a manner correspond with ours, and 
present us with a rude imitation of our own. In 
some of the ape kind the resemblance is so striking, 
that anatomists are puzzled to find in what part of 
the human body man's superiority consists ; and 
scarce any hut the metaphysician, who studies the 
mind, can draw the line that ultimately divides 
them. 
But if we compare their internal structure with 
our own, the likeness will be found still to increase, 
and we shall perceive many advantages they enjoy 
in common with us, above the lower tribes of na- 
ture. Like us, they are placed above the class 
