Your education, if it is disciplinary, ought also to teach you the value of clear thinking, that is, of exact definitions, clear propositions, well-considered opinions. What a flood of loose rhetoric, distorted fact, and unclear thinking is poured out upon us whenever a difficult question falls into popular discussion! You cannot find that people who assume to take part in the discussion have a clear definition in their minds of even what they conceive the main terms in the discussion to mean. They do not seem able to make a proposition which will bear handling so as to see what it is, and whether it is true or not. They cannot analyze even such facts as they have collected, and hence cannot draw inferences which are sound. It needs but little discussion of any great political or social question to show instances of this, and to show the immense importance of having in the community men of trained and disciplined intellects, who can think with some clearness and resist plain confusion of terms and thought. For instance, I saw the other day a long argument on an important public topic which turned upon the assertion and belief on the part of the writer that a mathematical ratio and a subjective opinion were things of the same nature and value. Perhaps, when he was at school, his father thought there was no use in studying algebra and geometry. It would not make so much difference if he would not now meddle with things for which he did not prepare himself, but it is this kind of person who is the pest of every science, traversing it with his whims and speculations; and perhaps I feel the more strongly the importance of this point because the political, economic, and social sciences suffer from the want of high discipline more than any others. I ought not to pass without mention here the mischief which is done in every science by its undisciplined advocates who, while admitted to its inner circle, distract its progress and throw it into confusion by neglect of strict principles, by incorrect analyses or classifications, or by flinching in the face of fallacies. They render the ranks unsteady and delay the march, and the reason is because they have never had rigorous discipline either before or since they enlisted.