All 4 Uses of

perceive

in

All Quiet on the Western Front

But as it is I perceive behind them only the suffering of the creature, the awful melancholy of life and the pitilessness of men.
Chpt 8 (definition 1)

perceive = view in a certain way so as to form a belief or opinion

When she perceives Franz's trouble she begins to bustle, and says: "Why did not someone say I was wanted?"
Chpt 10 (definition 2) *

perceives = becomes aware of

...life is simply one continual watch against the menace of death;—it has transformed us into unthinking animals in order to give us the weapon of instinct—it has reinforced us with dullness, so that we do not go to pieces before the horror, which would overwhelm us if we had clear, conscious thought—it has awakened in us the sense of comradeship, so that we escape the abyss of solitude—it has lent us the indifference of wild creatures, so that in spite of all, we perceive the positive in every moment,
Chpt 11 (definition 1) *

perceive = view in a certain way to see

And at night, waking out of a dream, overwhelmed and bewitched by the crowding apparitions, a man perceives with alarm how slight is the support, how thin the boundary that divides him from the darkness.
Chpt 11 (definition 1)

perceives = views in a certain way so as to form a belief or opinion

Definitions:

(1) (perceive as in: perceive the system as unfair)
to view in a certain way so as to form a belief or opinion

(2) (perceive as in: though blind, can perceive light)
to become aware of -- especially by using the senses (to see, hear, smell, feel, or taste)