The object of intellectual discipline is the establishment of a strong central authority in the mind by which all its powers are regulated and directed as the military forces of a nation are directed by the strategist who arranges the operations of a war. The presence of this strong central authority is made manifest in the unity and proportion of the results; when this authority is absent (it is frequently entirely absent from the minds of undisciplined persons, especially of the female sex), you have a chaos of complete confusion; when the authority without being absent is not strong enough to regulate the lively activity of the intellectual forces, you have too much energy in one direction, too little in another, a brigade where a regiment could have done the work, and light artillery where you want guns of the heaviest calibre. To establish this central authority it is only necessary, in any vigorous and sound mind, to exercise it. Without such a central power there is neither liberty of action nor security of possession. "The mind," says Locke, "should always be free and ready to turn itself to the variety of objects that occur, and allow them as much consideration as shall, for that time, be thought fit. To be engrossed so by one subject as not to be prevailed on to leave it for another that we judge fitter for our contemplation, is to make it of no use to us. Did this state of mind always remain so, every one would, without scruple, give it the name of perfect madness; and whilst it does last, at whatever intervals it returns, such a rotation of thoughts about the same object no more carries us forward toward the attainment of knowledge, than getting upon a mill-horse whilst he jogs on his circular track, would carry a man on a journey."