What is discussed is the tendency in many historians to write on the side of Protestants and Whigs, to praise revolutions provided they have been successful, to emphasize certain principles of progress in the past and to produce a story which is the ratification if not the glorification of the present.
    -Preface: The Whig Interpretation of History

It is part and parcel of the whig interpretation of history that it studies the past with reference to the present; and though there may be a sense in which this is unobjectionable if its implications are carefully considered, and there may be a sense in which it is inescapable, it has often been an obstruction to historical understanding because it has been taken to mean the study of the past with direct and perpetual reference to the present. Through this system of immediate reference to the present day, historical personages can easily and irresistibly be classed into the men who furthered progress and the men who tried to hinder it; so that a handy rule of thumb exists by which the historian can select and reject, and can make his points of emphasis.

There is an alternative line of assumption upon which the historian can base himself when he comes to his study of the past; and it is the one upon which he does seem more or less consciously to act and to direct his mind when he is engaged upon a piece of research. On this view he comes to his labours conscious of the fact that he is trying to understand the past for the sake of the past, and though it is true that he can never entirely abstract himself from his own age, it is none the less certain that this consciousness of his purpose is very different one from that of the whig historian, who tells himself that he is studying the past for the sake of the present. Real historical understanding is not achieved by the subordination of the past to the present, but rather by our making the past our present and attempting to see life with the eyes of another century than our own.

The value of history lies in the richness of its recovery of the concrete life of the past.

Our assumptions do not matter if we are conscious that they are assumptions, but the most fallacious thing in the world is to organize our historical knowledge upon an assumption without realizing what we are doing, and then to make inferences from that organization and claim that these are the voice of history. It is at this point that we tend to fall into what I have nicknamed the whig fallacy.

It is not sin in a historian to introduce a personal bias that can be recognized and discounted. The sin in historical composition is the organization of the story in such a way that bias cannot be recognized, and the reader is locked along with the writer in what is really a treacherous argument in a circle.