2013] THE CASE FOR PLURALISM AND BALANCING 537
Normative legal theories aim to say what the law should be. They make
proposals for changing the law and provide standards for evaluating existing
laws and other proposals. They currently dominate the leading legal
scholarship. It is important to understand what successful such theories
would look like. By making it possible to justify and criticize laws soundly,
normative legal theories undergird the legal system’s legitimacy.1
On one dimension, there are only two kinds of theories—“pluralist” and
“monist.” Robust pluralist theories take all relevant values into account and
balance them when they compete.2 A pluralist theory of contract law, for
example, might consider freedom of and freedom from contract,
contractual security, fairness, and Rule of Law values, including
administrability.3 The only relevant alternative type of theory is a monist
theory. A monist theory takes one and only one value into account and,
consequently, hopes to avoid balancing competing values. A monist theory
of contract law, for example, might rest on economic efficiency, autonomy,
promise, consent, transfer, Aristotelian ethics, or reliance.4
Over the last four decades, monist theories have proliferated, notably
those based on efficiency.5 Monists object to pluralist theories’ need to
1. See infra note 7 and accompanying text.
2. There are several varieties of pluralism. See infra Part II.B. This Article uses “pluralism”
in its robust, external sense.
3. See, e.g., STEVEN J. BURTON, ELEMENTS OF CONTRACT IN TERPRETATION, at xi, 2, 185
(2009) [hereinafter ELEMENTS]; MICHAEL J. TREBILCOCK, THE LIMITS OF FREEDOM OF
CONTRACT (1993); Melvin A. Eisenberg, The Theory of Contracts, in THE THEORY OF CONTRACT
LAW: NEW ESSAYS 206 (Peter Benson ed., 2001); see also Leon Trakman, Pluralism in Contract
Law, 58 BUFF. L. REV. 1031, 1062 (2010); Nathan Oman, Unity and Pluralism in Contract Law,
103 MICH. L. REV. 1483 (2005) (reviewing STEPHEN A. SMITH, CONTRACT THEORY (2004)).
Professor Gregory S. Alexander presents Aristotelian ethics as a kind of pluralism because it
encompasses several virtues. Gregory S. Alexander, Pluralism and Property, 80 FORDHAM L. REV.
4. See, e.g., CHARLES FRIED, CONTRACT AS PROMISE: A THEORY OF CONTRACTUAL
OBLIGATION (1981) (autonomy); GRANT GILMORE, THE DEATH OF CONTRAC T (1974)
(reliance); JAMES GORDLEY, THE PHILOSOPHICAL ORIGINS OF MODERN CONTRACT DO CTRINE
(1991) (Aristotelian ethics); RICHARD A. POSNER, ECONOMIC ANALYSIS OF LAW 93–142 (7th ed.
2007) (efficiency); STEPHEN A. SMITH, CONTRACT THEORY (2004) (promise); Randy E. Barnett,
A Consent Theory of Contract, 86 COLUM. L. REV. 269 (1986) (consent); Peter Benson, The Unity of
Contract Law, in THE THEORY OF CONTRACT LAW: NEW ESSAYS, supra note 3, at 118 (transfer);
Chapin F. Cimino, Virtue and Contract Law, 88 OR. L. REV. 703 (2009) (virtue). See generally
ROBERT A. HILLMAN, THE RICHNESS OF CONTRACT LAW: AN ANALYSIS AND CRITIQUE OF
CONTEMPORARY THEORIES OF CONTRACT LAW (1997). Professor Melvin A. Eisenberg has
suggested that Oliver Wendell Holmes, Jr. was a monist in a much broader way, encompassing
the entire common law. Melvin Aron Eisenberg, The Responsive Model of Contract Law, 36 STAN .
L. REV. 1107, 1108–09 (1984) (citing O.W. HOLMES, JR., THE COMMON LAW 49–59 (1881)).
5. “Efficiency” is not a unitary value. Versions of efficiency include Pareto optimality,
Pareto superiority, Kaldor–Hicks efficiency, and wealth maximization. Each of these versions
embodies a slightly different value. A well-done monist efficiency theory would em brace only