The most important theme of the book thus far in my mind is blindness. I say this because we already know Bigger a little more and find out what kind of a person he really is when faced with the kind of situations he's in.
Bigger starts seeing things & people differently. He see's himself differntly & has to try to act like everyone else to not get caught, do what regular people do. (pg.106) "Things were becoming clear; He would know how to act from know on. The thing to do was to act just like others acted, live how they lived, and while they were not looking, do what you wanted". Bigger cant see how to act really making him blind.
Bigger also see's people as blind now. Blind as in not seeing things cleary or not seeing the whole picture as he can. (pg.107) what he had done last night had proved that. Jan was blind. Mary had been blind, Mr. Dalton was blind. And Mrs. Dalton was blind;". They are blind because they do not see/know what really happened to Mary or that Bigger is involed.
Thats why this theme is the most important to me. We see what kind of a person he becomes after killing a person. We see how he thinks, acts, & feels now.