From a formal point of view there is nothing absurd about the investigation undertaken by Marx. It is a usual method of scientific analysis to regard a phenomenon not only as it exists, but also as it would be if one of its factors were altered, and, in comparing the hypothetical with the real phenomenon, to conceive the first as diverging from the second, which is postulated as fundamental, or the second as diverging from the first, which is postulated in the same manner. If I build up by deductive reasoning the moral rules which develop in two social groups which are at war one against another, and if I show how they differ from the moral rules which develop in a state of peace, I should be making something _analogous_ to the comparison worked out by Marx. Nor would there be great harm (although the expression would be neither fortunate nor accurate) in saying, in a figurative sense, that the _law_ of the moral rules in time of war is the same as that of the rules in time of peace, modified to the new conditions, and altered in a way which seems, ultimately, inconsistent with itself. As long as he confines himself to the limits of his hypothesis Marx proceeds quite correctly. Error could come in only when he or others confuse the hypothetical with the real, and the manner of conceiving and of judging with that of existing. As long as this mistake is avoided, the method is unassailable. But the formal justification is insufficient: we need another. With a formally correct method results may be obtained which are meaningless and unimportant, or mere mental tricks may be performed. To set up an arbitrary standard of comparison, to compare, and deduce, and to end by establishing a series of divergencies from this standard; to what will this lead? It is then, the _standard itself_ which needs justification: _i.e._ we need to decide what meaning and importance it may have for us.