Institutio Oratoria

While the battle still rages, the task of luring on our adversary when he has once committed himself to error, and of forcing him to commit himself as deeply as possible, even to the extent at times of being puffed up with extravagant hopes of success, requires great prudence and skill. It is, therefore, wise to conceal some of our weapons: for our opponents will often press their attack and stake everything on some imagined weakness of our own, and will give fresh weight to our proofs by the instancy with which they demand us to produce them.

It may even be expedient to yield ground which the enemy thinks advantageous to himself: for in grasping at the fancied advantage he may be forced to surrender some greater advantage: at times, too, it may serve our purpose to give him a choice between two alternatives, neither of which