The article focuses on the justification provided by classical contract theory for the right of states to enact laws and the corresponding obligation of political allegiance. At first the distinction between political authority and parental authority developed by John Locke in his seminal work "Two Treatises of Government" is explored. Thereafter ... it is discussed why the interests of individuals in the creation of a state fail to vindicate the exercise of governmental power. As regards David Hume's influential objections to contract theory, it is argued that the consent criterion of political legitimacy withstands his criticism. Hume cannot establish that the core idea of Locke's justificatory approach is wrong; he merely demonstrates that hardly any existing state meets the consent requirement. Finally the question is discussed which conditions a state must fulfil in order to be entitled to claim that its citizens tacitly approve of its authority.