It says in Parashath Shoftim: Justice, justice Shall you pursue. Why is the word "Justice" doubled?
It says in 'Od Yoseph Hai that, obviously, a person must cleave to truth and justice and distance him/herself from lies and falsehoods. This is a fundamental in Judaism. But just as a person must normally keep away from lying, there are times when he must keep away from the truth. As our Rabbis of blessed memory tell us: we must change [the facts] for the sake of peace.
This comes to teach us that a person should never say, "I am very righteous and only speak the truth and will never lie, even for the sake of peace". We must know that lying for the sake of peace is not only permitted, but is an obligation.
That is why the word "justice" is doubled. The first time it means "righteousness", and the second time "truth". When the verse tells us that we must pursue it, it is coming to tell us that in order to do righteousness in the world there are times you have to be in pursuit of truth to chase it away.
(See 'Od Yoseph Hai Derashoth, Parashath Shoftim)
