Demonstration is also something necessary, because a demonstration cannot go otherwise than it does, ... And the cause of this lies with the primary premises/principles.
The worst class of sum worked in the every-day world is cyphered by the diseased arithmeticians who are always in the rule of Subtraction as to the merits and successes of others, and never in Addition as to their own.
Thus, cases of injustice, and oppression, and tyranny, and the most extravagant bigotry, are in constant occurrence among us every day. It is the custom to trumpet forth much wonder and astonishment at the chief actors therein setting at defiance so completely the opinion of the world; but there is no greater fallacy; it is precisely because they do consult the opinion of their own little world that such things take place at all, and strike the great world dumb with amazement.
When I have heard him talking to Papa during the sittings for the picture, I have sat wondering whether it could be that he has no belief in anybody else, because he has no belief in himself.