Abstract: The rights to liberty championed by classical liberal and libertarian theorists may be supported as products of practical reason. The foundations for these rights rest initially on the idea that the separateness of persons is embedded in the circumstances of life that make justice a meaningful concept. We can discover the duties justice imposes on us through a procedure for identifying principles of justice based on the concept of reasonableness that supports a method for testing proposed principles for human interaction. This procedure, which I present as a contractualist method of ethical justification, vindicates principles that establish duties to others that also constitute rights to liberty and rule out some kinds of purported rights that cannot be justified through the proffered contractualist method.
Keywords: rights, liberty, liberalism, contractualism, justification