18. The 'Political-not-Metaphysical' Legacy

What this lecture covers

This lecture finishes the discussion of Rawls and then pulls back to survey the whole first part of the course: the Enlightenment's two commitments to individual rights and to science and reason. It traces how each commitment eroded over time, from Locke's certainty to Mill's fallibilism to the mature Rawls's retreat into a "political, not metaphysical" theory, and from Locke's workmanship model of ownership through Marx to Rawls's argument that our capacities are morally arbitrary.

After watching, you should be able to explain why Rawls's difference principle is philosophically underdetermined with respect to actual economic systems, state the idea of an overlapping consensus or incompletely theorized agreement, and describe why the workmanship idea about entitlement to what we make breaks down once it is separated from Locke's theological framework.

Key ideas

• Underdetermined difference principle: because it only asks what benefits the least advantaged, the principle is compatible with anything from a pure market system to heavy redistribution, so it does not, by itself, make Rawls an egalitarian.
• Harsanyi's challenge: economist John Harsanyi argued that a rational approach to risk behind the veil of ignorance would favor utilitarianism over Rawls's extreme risk-aversion, showing the theory's conclusions depend on contestable psychological assumptions.
• No unique answer: once you admit different assumptions about risk and psychology yield different principles, the neo-Kantian hope of one rationally compelled theory of justice collapses.
• Political, not metaphysical: the mature Rawls stops trying to derive justice from a single true metaphysics and instead looks for principles that people with very different worldviews can converge on.
• Overlapping consensus / incompletely theorized agreement: people can agree on a political arrangement, such as granting someone tenure or passing a bill, without agreeing on the reasons, an idea Shapiro also credits to legal scholar Cass Sunstein.
• Workmanship model: Locke's idea that making something confers ownership of it, originally grounded in the claim that we are like "miniature gods" acting under God's law.
• Secularizing workmanship fails: once workmanship is cut loose from its theological basis, as with Marx and later Rawls and Dworkin, it becomes hard to justify why anyone deserves more than anyone else for what they make or do.
• Moral arbitrariness and effort: if capacities are morally arbitrary, so is the will or work ethic used to exercise them, leaving no stable ground for rewarding effort.

Walkthrough

Introduction: Last Class Recap and Class Agenda (0:00)

Shapiro recaps the three Rawlsian principles and the L-shaped indifference curves from the previous lecture, then argues that Rawls's difference principle is far more underdetermined than it first appears. Because it is compatible with both pure markets and heavy state redistribution, it does not settle which economic system is just; Rawls treats that as an empirical question for political economy, not philosophy.

Course Recap (7:05)

The lecture steps back to review the course's arc through Enlightenment political theory, organized around two commitments: individual rights and science-and-reason as the basis of politics. Shapiro traces the shift from early Enlightenment certainty, in Descartes, Locke, and Hobbes, to Mill's fallibilism, where science means testing ideas in a marketplace of arguments rather than achieving certainty. He then explains why Rawls and Nozick's social contract theories echo the early Enlightenment's hope for a single rationally compelled answer, and why Kant himself was skeptical that political and social arrangements could ever be derived that way. Citing John Harsanyi's 1975 critique, Shapiro argues that different assumptions about risk produce different principles of justice, Rawls's maximin or Harsanyi's utilitarianism, which undermines the claim that there is one uniquely correct theory.

Political, Not Metaphysical (18:49)

Facing this problem, the mature Rawls shifts strategy toward a "political, not metaphysical" position, explained here partly through legal scholar Cass Sunstein's related idea of incompletely theorized agreement. Rather than requiring everyone to agree on deep metaphysical or scientific premises before agreeing on political arrangements, this approach looks for an overlapping consensus: outcomes that people with very different worldviews can each affirm, for their own separate reasons. Shapiro compares this to a university tenure vote or a legislative vote, where people agree on the outcome without agreeing on the justification, and likens the whole move to the secret ballot, where voters are not required to give reasons for their choices. He frames this as a major retreat from the Enlightenment's original ambition of grounding politics in scientifically compelled principles.

The Normative Idea of Individual Rights (28:35)

Turning to the Enlightenment's other core commitment, individual rights, Shapiro retraces Locke's workmanship model: God owns and knows his creation because he made it, and gives humans a similar capacity to acquire "maker's knowledge" and rights of ownership over what they make. He shows how this idea survived, secularized, through Marx's labor theory of value, and ran into trouble once critics pointed out that capitalists, spouses, and others also contribute to what a "worker" produces. Rawls pushes the critique further with his argument that differences between people are morally arbitrary, whether they stem from nature or nurture, so no one is straightforwardly entitled to what their capacities produce. Rawls tries to preserve some role for personal effort by distinguishing capacities from the use we choose to make of them, but Shapiro shows this fails, since the disposition to work hard is itself shaped by factors outside our control. He extends the point to Ronald Dworkin's related but ultimately similarly strained attempt to separate material resources from physical and mental powers. Shapiro closes by noting that this problem never arose for Locke, since for him differences between people were simply part of God's plan, and it only becomes intractable once the workmanship idea is secularized, leaving thinkers unable either to fully justify unequal reward or to give up on the intuition that effort should count for something.

Before you watch

• Review the difference principle and the Rawls, Bentham, and Pareto comparison from the previous lecture, since this class builds directly on both.
• Recall the course's account of Enlightenment commitments to individual rights and to science and reason, introduced with Hobbes and Locke earlier in the course.
• Be familiar with Locke's workmanship idea and Marx's labor theory of value.

Check your understanding

1. Why does Shapiro say the difference principle is compatible with both markets and heavy redistribution?
2. What is Harsanyi's objection to Rawls's assumptions about risk, and what does it imply about the search for a unique theory of justice?
3. What does "political, not metaphysical" mean, and how does the idea of an overlapping consensus relate to it?
4. Why does Locke's workmanship model avoid the problem of moral arbitrariness that Rawls runs into?
5. Why does Rawls's distinction between capacities and the use we make of them fail to rescue the idea that effort deserves reward?