pithy words in the style of a bestseller

In the third part of The Tenth Commandment by Lawrence Sanders, our protagonist Joshua Biggs has just participated in a ploy to get one guilty party to spill the refried beans on the other (arguably more guilty) and begins to wonder about justice and how it does not always seem absolute:

I should have been exultant but I wasn't. It was the morality of what I had done that was bothering me. All that chicanery and deceit. I would have committed almost any sin to demolish [primary guilty party], but conniving in the escape of [guilty party that was the object of the ploy] from justice was more than I had bargained for. And I had connived. I had worked almost as hard as [police office] to convince [guilty party that was the object of the ploy] to betray [primary guilty party]. It had to be done. But as [police officer] had said, [guilty party that was the object of the ploy] was going to walk. An accomplice to murder. Was that fair? Was that justice?
I realised I didn't really know what "justice" meant. It was not an absolute. It was not a colour, a mineral, a species. It was a human concept (what do animals know of justice?) and subject to all the vagaries and contradictions of any human hope. How can you define justice? It seemed to me that it was constant compromise, molded by circumstance.
I would make a terrible judge.

Edward X Delaney managed to find his own way of dealing with this dilemma, but Sanders unfortunately never wrote another novel featuring Joshua Biggs, so we'll never know what Mr. Biggs did.