From Chapter 10 of The Struggle for a Proletarian Party by James P. Cannon.
....From Chapter 10
....all of us, including the majority, have shown insufficient energy, initiative, etc. By that we acknowledge that we are not Bolsheviks in our habits and practice, but only striving to become such; slovenliness and slackness are Menshevik traits. But our theory, Marxism, is the only revolutionary theory in the world; there is nothing conservative about it. Can we be justly indicted for conservatism in our politics, that is, in the application of our theoretical principles? I do not believe our record justifies such an indictment. The essence of politics is to understand the realities of a given situation, to know what is possible and what is excluded; above all, to know what to do next—and to do it.
....The opposition, following Burnham, began to designate us as conservative only when we refused to accept a revision of the program of the Fourth International on the Russian question after the signing of the Soviet-Nazi pact, and instead, reaffirmed our fundamental position. Their whole case rests on this. From it they construe a conservative tendency in our whole past record. They also rail at our stick-in-the-mud attitude toward the fundamental concepts of Marxism—the class theory of the state, the class criterion in the appraisal of all political questions, the conception of politics, including war, as the expression of class interests, and so forth and so on. From all of this they conclude that we are “conservative” by nature, and extend that epithet to cover everything we have done in the past.
Such “conservatism,” which they consider a fault, we hold to be a virtue. We aim to “hold on” firmly to these principles which have been verified in the test of the greatest historic events, and which in our view constitute the only program of proletarian liberation. We have carefully examined the substitutes offered to us by Burnham. They are not the products of his own manufacture. He is not the inventor or originator of anything. The offerings of Burnham are shoddy stuff, and if you inspect them closely you will see on every item the trade mark of another class. Burnham is merely the broker of shopworn merchandise that has been palmed off on the workers time and again by bourgeois ideologists and always to the detriment of their struggle. We will have none of it. We stick to our own program. We accept no substitutes. If this be conservatism, make the most of it.