My major Vs Republic 2

I am a Criminal Justice major and I never really questioned it until reading the Republic Book 2. I never thought of justice as a necessary evil at all, in fact, I thought of it as the exact opposite. After reading the Republic Book 2 I see that justice isn't in the highest category of good. I'm not planning on changing my major or anything radical like that but it is interesting to have my perspective, on something I always thought was the ultimate good, changed. I am still sure that I want to continue into law enforcement and that it is the right thing not only for me but it is my way of helping the world, even if justice isn't that ultimate good.