How about this, from the March 15, 1955 Watchtower:
Perhaps one of the outstanding uses of illustrations is to side-step bias or prejudice or partiality. We are usually biased in our own favor. We tend to protect ourselves, our opinions, our actions, our cherished beliefs, and if anyone criticizes them we automatically defend them. Pride makes it hard for us to admit we are wrong. If it was a matter of conduct we make excuses or think of extenuating circumstances. It is not just a matter of logic, of reasoning on the situation. It is a question of emotion also. And emotion is not always reasonable. Oftentimes it wins the tug of war with logic. But if we can reason on the same situation without knowing we are involved, logic and reasoning can do their work unhindered by personal feelings. Here is where the illustration comes into play. It will side-step prejudice, sever the person from the event, put him in the position of an impartial observer with no personal stake involved, and will let him decide purely on the basis of right principles.
I think it sums up the Society pretty well.