Yeats
Partridge collects a book of Yeats poetry after killing a group attempting to hide art. The symbol is that he is beginning to feel things and desires it more.
Partridge's Death
John shoots his partner in the head with the Yeats poetry between him and Partridge. The symbol is that Partridge is willing to die for what he believes in, that emotions and art matter and are meaningful to human existence.
Empty Bed
John wakes up to see an empty bed next to his. It is where his wife once slept. The symbol is that he is beginning to remember her and desire her to be with him once again.
Injections
The injections that John and each person takes cuts them off from feeling anything. It is a symbol of the government's control over the people in order to reign supreme and become the law.
Prozium
We see John drop his dosage of Prozium before entering the city for the day. It is crushed upon his heel and it is a symbol that he will not go back to the life of being drugged and without feelings.