The following are excerpts from a chapter about the differences in animals and humans, and how we detest certain characteristics and value others. This is not a quick read, but it fascinated me. 

“Of eyes, we shall find those ugliest which have in them no expression nor life whatever, 

but a corpse-like stare, 

or an indefinite meaningless glaring.

 The most vivid example of that is in insects; but also like in owls or chameleons. 

The next in ugliness are the eyes that gain vitality, but only by means of the expression of intense malignity like we see in the serpent and alligator. 

Now in humans the superior beauty consists always in greater or less sweetness and gentleness and intellect.   

Let’s consider the mouth, another source of expression, 

we find it ugliest where it has none, for example in fish. Or where it becomes a destructive instrument, as again in the alligator or carnivores that lose what beauty they have, in actions of snarling and biting.

Now we come to humans, the mouth is given most definitely as a means of expression, beyond and above its animal functions. 

We are creatures created in the image of God, so one would expect our faces to display far more than simple animals. But evil takes a toll and changes us. 

Those signs of evil which are commonly and most revealed on the human features are – 

The signs of pride

Of sensuality

Of fear

And of cruelty.

Any one of which will destroy the ideal character of the countenance and body.

 The first is pride, it is perhaps the most destructive of all the four, seeing it is the undermost and original story of sin.

The second destroyer of human beauty is the appearance of sensual character, more difficult to trace, owing to its peculiar subtlety. 

Respecting those two other vices of the human face, the expressions of fear and ferocity, these only occasionally enter into the conception of character. 

Among the children of God, while there is always that fearful apprehension of His majesty, 

and that sacred dread of all offense to Him, 

which is called the fear of God, 

yet of real and essential fear, there is not any, 

but a clinging of confidence to Him, 

as their Rock, Fortress and Deliverer; 

and perfect love, and casting out of fear, 

so that it is not possible that while the mind is rightly bent on Him, there should be dread of anything, either earthly or supernatural. 

And lastly, Ferocity, which is of all passions the least human. 

Ferocity has no excuse or alleviation, 

but it is the pure essence of charging tiger and demon, 

and it casts on the human face the paleness like of the “horse of death” and the ashes of hell.”

John Ruskin.