… is from pages 2-3 of Tulane University philosopher Eric Mack’s 2018 book, Libertarianism :
According to the libertarian, at least as a first approximation, ordinary norms of morality require that harmful force or the threat of such force be used against individuals only to defend against or extract restitution for, or to punish initiated force or threat of force, or to enforce compliance with voluntary contracts. Hence, state use of force and the treat of force must also be confined to the functions of defense, restitution, punishment, and the enforcement of contract. Libertarians maintain that the enforcement of a framework within which individuals are secure in their persons, possessions, and contractual arrangements is the key condition for the emergence of a peaceful, tolerant, and prosperous social and economic order. Radical restriction on state action is the key to a flourishing cooperative society.
DBx: It’s commonplace for people who are hostile to libertarianism and classical liberalism to respond to an introductory description of libertarianism, such as this one offered by Eric, by noting that the application of such an ideal in reality requires that substantive content be given to concepts such as restitution (e.g., “Are the sins of the parents inherited by the children?”), possessions (e.g., “Does Smith’s property in his home include the possession of the ability to exclude his neighbors from partying loudly on Tuesday nights? Or do Smith and his neighbors possess the right to party loudly on Tuesday nights?”), and “persons” (e.g., “Do pregnant women have the right to terminate their pregnancies on day 279? Or is each fetus on that day a person with a right not to be killed? What about on or after day 90? Or day one? And do biological fathers have any say in the matter?”)
Of course these and an almost-literally countless number of other detailed questions must be answered, and answers given today can – and often do – change as time passes. Also, reasonable people can and do disagree over what the details of the answers are.
Every sensible libertarian understands and accepts this reality.
Nothing about this reality is unique to libertarianism. Each and every moral and political philosophy must begin with a set of general principles whose applications in reality are not fully determined by any statement, no matter how eloquent, of its general principles. Yet it’s vitally important both to begin with sound general principles – principles that, when good-faith efforts are made to follow them, lead generally to good results – and to articulate these general principles with clarity and concision that make them useful guides for how to answer reality’s multitude of challenging questions.