Variant translation: To introduce into the philosophy of war a principle of moderation would be an absurdity.
As quoted in The Campaign of 1914 in France and Belgium‎ (1915) by George Herbert Perris, p. 56.
Source: On War (1832), Book 1, Chapter 1, Section 3, Paragraph 3

“Modern wars are seldom fought without hatred between nations; this serves more or less as a substitute for hatred between individuals.”

Carl von Clausewitz book On War

On War (1832), Book 2

“Any complex activity, if it is to be carried on with any degree of virtuosity, calls for appropriate gifts of intellect and temperament. If they are outstanding and reveal themselves in exceptional achievements, their possessor is called a 'genius.”

Carl von Clausewitz book On War

On War (1832), Book 1

“Action in war is like movement in a resistant element. Just as the simplest and most natural of movements, walking, cannot easily be performed in water, so in war it is difficult for normal efforts to achieve even moderate results.”

Carl von Clausewitz book On War

Source: On War (1832), Book 1, Ch. 7, as translated by Michael Howard and Peter Paret (1976).

“Determination in a single instance is an expression of courage; if it becomes characteristic, a mental habit. But here we are referring not to physical courage but to courage to accept responsibility, courage in the face of a moral danger. This has often been called courage d'esprit, because it is created by the intellect. That, however, does not make it an act of the intellect: it is an act of temperament. Intelligence alone is not courage; we often see that the most intelligent people are irresolute. Since in the rush of events a man is governed by feelings rather than by thought, the intellect needs to arouse the quality of courage, which then supports and sustains it in action.
Looked at in this way, the role of determination is to limit the agonies of doubt and the perils of hesitation when the motives for action are inadequate.”

Carl von Clausewitz book On War

Source: On War (1832), Book 1, Chapter 3.

“Obstinacy is a fault of temperament. Stubbornness and intolerance of contradiction result from a special kind of egotism, which elevates above everything else the pleasure of its autonomous intellect, to which others must bow.”

Carl von Clausewitz book On War

On War (1832), Book 1

“Blind aggressiveness would destroy the attack itself, not the defense.”

Carl von Clausewitz book On War

On War (1832), Book 1

“Thus it has come about that our theoretical and critical literature, instead of giving plain, straightforward arguments in which the author at least always knows what he is saying and the reader what he is reading, is crammed with jargon, ending at obscure crossroads where the author loses its readers. Sometimes these books are even worse: they are just hollow shells. The author himself no longer knows just what he is thinking and soothes himself with obscure ideas which would not satisfy him if expressed in plain speech.”

Carl von Clausewitz book On War

On War (1832), Book 2

“The state of crisis is the real war; the equilibrium is nothing but its reflex.”

Carl von Clausewitz book On War

On War (1832), Book 3

“War is an act of violence pushed to its utmost bounds.”

Carl von Clausewitz book On War

Variant translation: War is an act of violence which in its application knows no bonds.
As quoted in The Campaign of 1914 in France and Belgium‎ (1915) by George Herbert Perris, p. 56.
Source: On War (1832), Book 1, Chapter 1, Section 3, Paragraph 8

“…any move made in a state of tension will be of more important, and will have more results, than it would have made in a state of eqilibrium. In times of maximum tension this importance will rise to an infinite degree.”

Carl von Clausewitz book On War

On War (1832), Book 3

“…self-reliance is the best defence against the pressures of the moment.”

Carl von Clausewitz book On War

On War (1832), Book 1

“The worst of all conditions in which a belligerent can find himself is to be utterly defenseless.”

Carl von Clausewitz book On War

On War (1832), Book 1

“Boldness will be at a disadvantage only in an encounter with deliberate caution, which may be considered bold in its own right, and is certainly just as powerful and effective; but such cases are rare.”

Carl von Clausewitz book On War

On War (1832), Book 3