Antithesis is a species of word painting. It is to an argument what light and shade are to a painting. There can, therefore, be no argument without antithesis in some form. It may be defined, contrasting or placing in opposition opinions, sentiments, and ideas. The following are examples:

Paine.Junius.
"At home and abroad." "A government of our own is our natural right; and when a man seriously reflects on the precariousness of human affairs, he will become convinced that it is infinitely wiser and safer to form a constitution of our own in a cool, deliberate manner, while we have it in our power, than to trust such an interesting event to time and chance. If we omit it now, some Massanello may hereafter arise, who, laying hold of popular disquietudes, may collect together the desperate and discontented, and, by assuming to themselves the powers of government, finally sweep away the liberties of the continent like a deluge."—C. S. "At home and abroad." "If we see them obedient to the laws, prosperous in their industry, united at home and respected abroad, we may reasonably presume that their affairs are conducted by men of experience, abilities, and virtue. If, on the contrary, we see an universal spirit of distrust and dissatisfaction, a rapid decay of trade, dissensions in all parts of the empire, a total loss of respect in the eyes of foreign powers, we may pronounce, without hesitation, that the government of that country is weak, distracted, and corrupt."—Let. 1.

As would naturally be expected from what has already been brought forward, in regard to the mental constitution of Mr. Paine, he abounds in this figure and style of argumentation; and it is the same with Junius. Sentence after sentence, and period after period, are in antithesis. The expressions, "On the one hand, and on the other," "At home and abroad," "On this side, and on that," are the constant companions of both. Hence the method, also, in both, of bringing forward contradictions in the conduct and character of individuals, or in any proposition they are attacking. This is the language, also, of ridicule; the contradiction makes it absurd, the incongruity ridiculous. Antithesis is, therefore, an argumentative figure of speech, in which contrast or comparison is made to present an image of things or principles to the mind. It is to rhetoric what light and shade are to painting. In no other way can a writer paint a picture. Hence, when Mr. Paine says, "Were I disposed to paint a contrast," and when Junius says, "Imagine what you might be, and then reflect upon what you are," they reveal the gift of that tremendous power they exhibit in their productions.

It is from this constitutional arrangement of the mind which makes a man a good mathematician. For, if one will trace a mathematical process of reasoning, he will find it to be a system of comparisons or antitheses—and nothing else—having foundation primarily in equality. The idea of equality is the origin of mathematics. It was, therefore, a mathematician who wrote Junius. We can not go wrong in this conclusion, for we reason from first principles, and we would expect to find his style and language assuming mathematical preciseness, and only equaled by Mr. Paine in argumentation.

From what has already been said, we would expect to find the frequent use of the dilemma, and the reductio ad absurdum—or, that the contrary of what is true leads to the absurd.

Paine.Junius.
"There is something exceedingly ridiculous in the composition of monarchy; it first excludes a man from the means of information, yet empowers him to act in cases where the highest judgment is required. The state of a king shuts him from the world, yet the business of a king requires him to know it thoroughly; wherefore, the different parts, by unnaturally opposing and destroying each other, prove the whole character to be absurd and ridiculous." "The right of election is the very essence of the constitution. To violate that right, and, much more, to transfer it to any other set of men, is a step leading immediately to the dissolution of all government. So far forth as it operates, it constitutes a House of Commons which does not represent the people. A House of Commons so formed would involve a contradiction, and the greatest confusion of ideas; but there are some ministers, my lord, whose views can only be answered by reconciling absurdities, and making the same proposition which is false and absurd in argument true in fact."—Let. 11.

I give the following dilemmas:

Paine.Junius.
"If you make the necessary demand at home, your party sinks; if you make it not, you sink yourself; to ask it now is too late, and to ask it before was too soon; and, unless it arrive quickly, will be of no use. In short, the part you have to act can not be acted."—Crisis, ii. "This confession reduces you to an unfortunate dilemma. By renewing your solicitations, you must either mean to force your country into a war at a most unseasonable juncture, or, having no view or expectation of that kind, that you look for nothing but a private compensation to yourself."—Let. 25.

But those methods of argumentation are only a species of antithesis, and may all be reduced to the one fundamental form of comparison. This may remind us of the fact that all improvement arises from comparison, whether in language, government, or personal experience.