From Carl von Clausewitz, On War, trans. Michael Howard and Peter Paret (Princeton: Princeton University Press), 1976/1984, p89; p.101 in Knopf's "Everyman's Library" edition.
28. THE CONSEQUENCES FOR THEORY
War is more than a true chameleon that slightly adapts its characteristics to the given case. As a total phenomenon its dominant tendencies always make war a [remarkable (1976) or paradoxical (1984)] trinity--composed of primordial violence, hatred, and enmity, which are to be regarded as a blind natural force; of the play of chance and probability within which the creative spirit is free to roam; and of its element of subordination, as an instrument of policy, which makes it subject to reason alone.
The first of these three aspects mainly concerns the people; the second the commander and his army; the third the government. The passions that are to be kindled in war must already be inherent in the people; the scope which the play of courage and talent will enjoy in the realm of probability and chance depends on the particular character of the commander and the army; but the political aims are the business of government alone.
These three tendencies are like three different codes of law, deep-rooted in their subject and yet variable in their relationship to one another. A theory that ignores any one of them or seeks to fix an arbitrary relationship between them would conflict with reality to such an extent that for this reason alone it would be totally useless.
Our task therefore is to develop a theory that maintains a balance between these three tendencies, like an object suspended between three magnets.
What lines might best be followed to achieve this difficult task will be explored in the book on the theory of war [Book Two]. At any rate, the preliminary concept of war which we have formulated casts a first ray of light on the basic structure of theory, and enables us to make an initial differentiation and identification of its major components.