We grow up from boyhood; our minds open; we go into the world; we hear what men say, or read what they put in print; and thus a profusion of matters of all kinds is discharged upon us. Some sort of an idea we have of most of them, from hearing what others say; but it is a very vague idea, probably a very mistaken idea. Young people, especially, because they are young, colour the assemblage of persons and things which they encounter with the freshness and grace of their own springtide, look for all good from the reflection of their own hopefulness, and worship what they have created. Men of ambition, again, look upon the world as a theatre for fame and glory, and make it that magnificent scene of high enterprise and august recompence which Pindar or Cicero has delineated. Poets, too, after their wont, put their ideal interpretation upon all things, material as well as moral, and substitute the noble for the true. Here are various obvious instances, suggestive of the discipline which is imperative, if the mind is to grasp things as they are, and to discriminate substances from shadows. For I am not concerned merely with youth, ambition, or poetry, but with our mental condition generally. It is the fault of all of us, till we have duly practised our minds, to be unreal in our sentiments and crude in our judgments, and to be carried off by fancies, instead of being at the trouble of acquiring sound knowledge.In consequence, when we hear opinions put forth on any new subject, we have no principle to guide us in balancing them; we do not know what to make of them; we turn them to and fro, and over, and back again, as if to pronounce upon them, if we could, but with no means of pronouncing. It is the same when we attempt to speak upon them: we make some random venture; or we take up the opinion of some one else, which strikes our fancy; or perhaps, with the vaguest enunciation possible of any opinion at all, we are satisfied with ourselves if we are merely able to throw off some rounded sentences, to make some pointed remarks on some other subject, or to introduce some figure of speech, or flowers of rhetoric, which, instead of being the vehicle, are the mere substitute of meaning. We wish to take a part in politics, and then nothing is open to us but to follow some person, or some party, and to learn the commonplaces and the watchwords which belong to it....
John Henry Newman, The Idea of a University, Part 2, "Discipline of Mind".
