"The great art of knowledge," says Duncan, "lies in managing with skill the capacity of the intellect, and contriving such helps, as, if they strengthen not its natural powers, may yet expose them to no unnecessary fatigue.

When ideas become very complex, and by the multiplicity of their parts grow too unwieldy to be dealt with in the lump, we must ease the view of the mind by taking them to pieces, and setting before it the several portions separately, one after an other.

By this leisurely survey we are enabled to take in the whole; and if we can draw it into such an orderly combination as will naturally lead the attention, step by step, in any succeeding consideration of the same idea, we shall have it ever at command, and with a single glance of thought be able to run over all its parts."-- _Duncan's Logic_, p.

37, Hence we may infer the great importance of method in grammar; the particulars of which, as Quintilian says, are infinite.[44] 21.

Words are in themselves but audible or visible signs, mere arbitrary symbols, used, according to common practice and consent, as significant of our ideas or thoughts.[45] But so well are they fitted to be made at will the medium of mental conference, that nothing else can be conceived to equal them for this purpose.