“The progress of Science universally is retarded, because sufficient attention is not paid to explaining essentials in particular and exactly to define the terms employed.”—Euclid.

“The first care of the sage should be to discover the true character of his pupils. By his questions he should assist them to explain their own ideas and by his answers he should compel them to perceive their falsities. By accurate definitions he should gradually dispel the incongruities in their earlier education and by his subtlety in arousing their doubts, he should redouble their curiosity and eagerness for information; for the art of the instructor consists in inciting his pupils to that point at which they cannot endure their manifest ignorance.

“Many, unable to undergo this trial and confounded by offended self-conceit and lacking the fortitude to sustain correction, forsake their master, who should not be eager to recall them. Others who learn from humiliation to distrust themselves should no longer have snares spread for their vanity. The master should speak to them neither with the severity of a censor nor with the haughtiness of a sophist, nor deal in harsh reproaches nor importunate complaints; his discourse should be the language of reason and friendship in the mouth of experience.”—Socrates.