Of course, in legal matters, the requirement is honesty, that is sticking to the facts at least as much of them as are known or remembered (although the memory of many tends to faulty). However, superimposed on that is frequently the implicit requirement to be, well, sincere. Regularly lawyers coach their clients in the rudiments of the facial expressions, tone of voice, pacing of conversation, and body language to appear sincere.
Yet, as R. Jay Magill, Jr. hammers in his new book "Sincerity," that social construct of being sincere is not a Platonic universal or absolute in human affairs. It was cooked up as important during the Protestant reformation when leaders of the Roman Catholic Church were accused of not being sincere. For example, they peddled worthless indulgences which were billed as allowing miscreants to enter heaven.
Magill notes that the astute Machiavelli told his imaginary prince that it was useful to adopt the visage of sincerity but not advisable to attempt to have what one said align with action. Funny, though, that the legal system seems to treasure sincerity. It is in the self-interest of the convicted to express sincere remorse. The lack of it could get that person more time in the slammer or even the death penalty.
For that very reason the world waits to hear the sentence for convicted insider trader Rajat Gupta. He contends to this day that he is not guilty. He is defiant about his innocence. Those 200 letters from folks like Bill Gates which have been sent on his behalf may do no good. After all, the legal system cottons to sincere expression of remorse and a sincere desire to conform with society's moral code.
Will the strange requirement for sincerity be changed in the future?