A resource which can be a basis for the possession of power or of the ability to coerce is the control of and ability to use means of applying force or physical constraint. Employing force or physical constraint is itself, of course, a relatively straightforward way of getting another person to pursue a course of action he would not otherwise have pursued. I shall use either of these expressions to cover any exercise which reduces the range of actions actually open to an individual. (No other way of getting others to do things does this, as we shall see. Power, persuasion and the exercise of authority all work on the individual's will—in the case of power, by altering the incentives attached to the options; in the case of persuasion and the exercise of authority, by altering the individual's attitudes to the options—without reducing the range of options actually available to him.) The ways in which the range of available options may be reduced include restriction of the individual's movements (incarceration in a prison cell; confinement in a straitjacket); destruction, confiscation, removal, etc., of any of the necessary physical means of pursuing a course of action; and affecting the individual in such a way that he becomes literally incapable of doing certain acts (torture may do this, for example).
Another way of putting the matter is to say that when A employs force on B, B's decisions 'are irrelevant to the course of events which affect him'. Force is the only way of getting people to do things they would not otherwise have done, of which it may be properly said that, because of A's actions, B has no choice (with respect to the excluded options).
(Michael Taylor, Community, Anarchy and Liberty [Cambridge: Cambridge University Press, 1982], 19-20 [italics in original; footnote omitted])
