Hans J. Morgenthau,
Politics Among Nations: The Struggle for Power and Peace
Fifth Edition, Revised, (New York: Alfred A. Knopf, 1978, pp. 4-15
SIX PRINCIPLES OF POLITICAL REALISM
Political realism believes that politics, like society in general, is governed by objective
laws that have their roots in human nature. In order to improve society it is first necessary
to understand the laws by which society lives. The operation of these laws being
impervious to our preferences, men will challenge them only at the risk of failure.
Realism, believing as it does in the objectivity of the laws of politics,
must also believe in
the possibility of developing a rational theory that reflects, however imperfectly and one-
sidedly, these objective laws. It believes also, then, in the possibility of distinguishing in
politics between truth and opinion-
between what is true objectively and rationally,
supported by evidence and illuminated by reason, and what is only a subjective judgment,
divorced from the facts as they are and informed by prejudice and wishful thinking.
Human nature, in which the laws of politics have their roots, has not changed since the
classical philosophies of China, India, and Greece endeavored to discover these laws.
Hence, novelty is not necessarily a virtue in political theory, nor is old age a defect. The
fact that a theory of politics, if there be such a theory, has never been heard of before
tends to create a presumption against, rather than in favor of, its soundness. Conversely,
the fact that a theory of politics was developed hundreds or even thousands of years
ag~as was the theory of the balance of power-does not create a presumption that it must
be outmoded and obsolete. A theory of politics must be subjected to the dual test of
reason and experience. To dismiss such a theory because it had its flowering in centuries
past is to present not a rational argument but a modernistic prejudice that takes for
granted the superiority of the present over the past. To dispose of the revival of such a
theory as a "fashion" or "fad" is tantamount to assuming that in matters political we can
have opinions but no truths.
For realism, theory consists in ascertaining facts and giving them meaning through
reason. It assumes that the character of a foreign policy can be ascertained only through
the examination of the political acts performed and of the foreseeable consequences of
these acts. Thus we can find out what statesmen have actually done, and from the
foreseeable consequences of their acts we can surmise what their objectives might have
Yet examination of the facts is not enough.
To give meaning to the factual raw material of
foreign policy, we must approach political reality with a kind of rational outline, a map
that suggests to us the possible meanings of foreign policy. In other words, we put
ourselves in the position of a statesman who must meet a certain problem of foreign
policy under certain circumstances, and we ask ourselves what the rational alternatives
are from which a statesman may choose who must meet this problem under these