The quarter[back] is, under the captain, the director of the game. With the exception of one or two uncommon and rare plays, there is not one of any kind, his side having the ball, in which it does not pass through his hands. The importance of his work it is therefore impossible to overstate. He must be, above all the qualifications of brains and agility usually attributed to that position, of a hopeful or sanguine disposition. He must have confidence in his centre himself, and, most of all, in the man to whom he passes the ball. He should always believe that the play will be a success.To repeat: The quarterback "must be, above all..., of a hopeful or sanguine disposition." What a gloriously unique way of putting it.
Quote legwork courtesy of the always-must-read Chris Brown from Smart Football.