"The believer in the possibility of a science of history is not called upon to hold either the doctrine of predestined events, or that of freedom of the will; and the only positions which, in this stage of the inquiry, I shall expect him to concede are the following: That when we perform an action, we perform it in consequence of some motive or motives; that those motives are the results of some antecedents; and that, therefore, if we were acquainted with the whole of the antecedents, and with all the laws of their movements, we could with unerring certainty predict the whole of their immediate results. This, unless I am greatly mistaken, is the view which must be held by every man whose mind is unbiased by system, and who forms his opinions according to the evidence actually before him. … Rejecting, then, the metaphysical dogma of free will and, the theological dogma of predestined events, we are driven to the conclusion that the actions of men, being determined solely by their antecedents, must have a character of uniformity, that is to say, must, under precisely the same circumstances, always issue in precisely the same results. And as all antecedents are either in the mind or out of it, we clearly see that all the variations in the results—in other words, all the changes of which history is full, all the vicissitudes of the human race, their progress or their decay, their happiness or their misery—must be the fruit of a double action; an action of external phenomena upon the mind, and another action of the mind upon the phenomena. These are the materials out of which a philosophic history can alone be constructed. On the one hand, we have the human mind obeying the laws of its own existence, and, when uncontrolled by external agents, developing itself according to the conditions of its organization. On the other hand, we have what is called Nature, obeying likewise its laws; but incessantly coming into contact with the minds of men, exciting their passions, stimulating their intellect, and therefore giving to their actions a direction which they would not have taken without such disturbance. Thus we have man modifying nature, and nature modifying man; while out of this reciprocal modification all events must necessarily spring. The problem immediately before us is to ascertain the method of discovering the laws of this double modification." _H. T. Buckle, History of Civilization in England, chapter 1._