What is the meaning of the initiation of physical force?

”Man’s rights can be violated only by the use of physical force. It is only by means of physical force that one man can deprive another of his life, or enslave him, or rob him, or prevent him from pursuing his own goals, or compel him to act against his own rational judgment. The precondition of a civilized society is the barring of physical force from social relationships—thus establishing the principle that if men wish to deal with one another, they may do so only by means of reason: by discussion, persuasion and voluntary, uncoerced agreement.” — AYN RAND, The Nature of Government

In a political context, freedom has only one meaning — freedom from the initiation of physical force by others. By initiation is meant those who start the use of force to achieve their ends, i.e., a bank robber. Only the initiation of force can one stop one’s mind, rendering useless as a means of survival. Only by the initiation of force can one be prevented from speaking, or robbed of their possessions, or murdered. Only through the initiation of force can an individual’s rights be violated.

Can men use force in self-defense?

To use force in retaliation — in self-defense against those who initiate it — is not a moral option, but a moral requirement. A moral man has nothing to gain when a man tries to kill him, but he has much to lose if he does not defend himself. The use of force, in and of itself, is not evil — but to initiate (start) force is. Contrary to the doctrines of the pacifists, using force in self-defense is a good.

Any man (or group of men) who initiates force against others is a dictator — a monster — and should be treated as such, to the extent he initiates force.

What is the purpose of government under capitalism?

If a society left the retaliatory use of force in the hands of individual citizens, it would degenerate into mob rule, lynch law and an endless series of bloody private feuds or vendettas. If physical force is to be barred from social relationships, men need an institution charged with the task of protecting their rights under an objective code of rules. This is the task of a government—of a proper government—its basic task, its only moral justification and the reason why men do need a government. A government is the means of placing the retaliatory use of physical force under objective controli.e., under objectively defined laws.” — AYN RAND, “The Nature of Government

Under capitalism, a proper government’s fundamental responsibility is to protect the rights of the individual, by banning the initiation of physical force, thus making all relations between men voluntary, i.e., free from the threat of violence and fraud.

Man’s state in nature, where every man is allowed complete discretion in the retaliatory use of force, according to the laws of the jungle, is anarchy — perpetual civil war and gang warfare. If there were no legal agency to carry out such a task, each man would be forced to carry out retaliation at his discretion.