 In A Theory of Justice Rawls provides a “Kantian Interpretation” of the original position and the principles of justice (TJ §§ 40, 78). The Kantian interpretation is a precursor to Rawls’s Kantian constructivism (CP, ch. 16), and his later political constructivism (PL, ch.3). Rawls says that for Kant, “a person is acting autonomously when the principles of his action are chosen by him as the most adequate possible expression of his nature as a free and equal rational being” (TJ 252/222). What is missing from Kant, Rawls says, is an attempt to show how moral principles express our nature. “This defect is made good [by] the original position” (TJ 255 /224). The original position can be interpreted as a “procedural interpretation” of our nature as free and equal rational beings, and therewith of Kant’s conception of autonomy and the categorical imperative (TJ 256 /226). For in the original position, because of the veil of ignorance and other moral constraints, the parties’ choice is made “independent of natural contingencies and accidental social circumstances” (TJ 515/451); thus the principles of justice are not chosen “heteronomously,” on the basis of our social position, natural endowments, particular wants, or the particular kind of society we live in (TJ 252/222). Instead, the parties are all represented in the same way, as free and equal rational persons with a capacity for a sense of justice who choose principles of justice subject to all relevant moral conditions. Rawls says that the original position might thus be regarded as incorporating “conditions that best express their nature as free and equal rational beings.” On a Kantian view, our moral nature is defined by the moral powers, our capacities for practical reasoning, to be rational and reasonable. The moral powers are the relevant capacities of practical reasoning that relate to justice. “Acting autonomously is acting from principles that we would consent to as free and equal rational beings” (TJ 516/453). The description of the original position expresses “what it means to be a free and equal rational being,” and even “resembles the point of view of noumenal selves” (TJ 255–256/225).