While Molinari takes a more-or-less value-free economic approach, others took a Lockean natural rights approach. Herbert Spencer wrote about The Right to Ignore the State. Michael Bakunin stressed the right to opt out of any association. Lysander Spooner starts with Locke's argument for organized defense of rights, and draws the logical conclusions based on consent that Locke evaded.

Although it is the right of anybody and everybody - of any one man, or set of men, no less than another - to repel injustice, and compel justice, for themselves, and for all who may be wronged, yet to avoid the errors that are liable to result from haste and passion, and that everybody, who desires it, may rest secure in the assurance of protection, without a resort to force, it is evidently desirable that men should associate, so far as they freely and voluntarily can do so, for the maintenance of justice among themselves, and for mutual protection against other wrong-doers. It is also in the highest degree desirable that they should agree upon some plan or system of judicial proceedings, which, in the trial of causes, should secure caution, deliberation, thorough investigation, and, as far as possible, freedom from every influence but the simple desire to do justice.

Yet such associations can be rightful and desirable only in so far as they are purely voluntary. No man can rightfully be coerced into joining one, or supporting one, against his will. His own interest, his own judgement, and his own conscience alone must determine whether he will join this association, or that; or whether he will join any. If he chooses to depend, for the protection of his own rights, solely upon himself, and upon such voluntary assistance as other persons may freely offer to him when the necessity for it arises, he has a perfect right to do so. ...

Certainly no man can rightfully be required to join, or support, an association whose protection he does not desire. Nor can any man be reasonably or rightfully expected to join, or support, any association whose plans, or method of proceeding, he does not approve... To join or support one that, in his opinion, would itself do injustice, would be criminal. He must, therefore, be left at the same liberty to join, or not to join, an association for this purpose, as for any other, according as his own interest, discretion, or conscience shall dictate. - Spooner, Natural Law