Constitutional Empiricism: Quasi-Neutral Principles and Constitutional Truths

100 Pages Posted: 21 Nov 2003


This Article describes and analyzes "constitutional empiricism," a trend, instituted by the Rehnquist Court, which is characterized by judicial reliance in constitutional review on empirical and scientific data, conventions, and processes. The Court has historically relied upon traditional sources, such as text, structure, and history, to interpret constitutional powers and rights. In the continuing search for neutrality and objectivity, however, the Court has recently turned not only to social science and other empirical data, which have become common sources of interpretation in constitutional cases, but also to the precepts and methods of scientific and empirical inquiry.

Constitutional empiricism is a method of constitutional interpretation which seeks to imitate scientific inquiry. The Court purports, for example, to be able to distinguish, by reference to empirical observation, "real" from sham legislative predicates. It now routinely empirically tests these predicates as if they were legislative hypotheses, predictions, theories, and falsifiable causal claims. Beyond this empirical testing of legislative predicates, empiricism is also manifested in the Rehnquist Court's efforts to quantify constitutional norms found in provisions as disparate as the Due Process Clause, the Establishment Clause, and the Cruel and Unusual Punishments Clause, among others. Thus, for example, the constitutionality of punitive damages awards is determined by reference to newly announced due process ratios; the validity of vouchers depends in large part upon an "Establishment Equation"; and whether execution of the mentally retarded is "cruel and unusual" depends upon the "direction of change" observed in state legislative outputs.

Drawing upon debates in the philosophy of science discipline, the Author argues that constitutional empiricism does not provide long-sought neutral methods and principles for constitutional interpretation. Empiricism is based upon a host of subjective choices that affect not only which questions will be answered empirically, but also the collection, categorization, and ultimate interpretation of data. Thus, the precepts of empiricism do not, as would appear, function as a set of "neutral principles." In fact, the Author argues, far from propelling constitutional interpretation into the twenty-first century, empiricism has been utilized, thus far, to draw attention away from a return to the sort of formalism and conceptualism that characterized early eras of constitutional interpretation. More generally, the Author contends that empirical methods are ill-suited to the discovery of constitutional meaning. Because it filters evidence, fails to provide standards for separating "good" empirical results from "bad" results, and demands that hypotheses be legally "correct," constitutional empiricism does not advance constitutional knowledge in the same manner that empirical methods advance scientific knowledge. Perhaps even more disturbing, however, the Author argues that finding constitutional truths empirically threatens to further compress an already narrow constitutional discourse.

Keywords: constitutional interpretation, empirical, philosophy of science, empiricism, constitutional meaning, realism, formalism, falsification, daubert

JEL Classification: K1, K3

Suggested Citation

Zick, Timothy, Constitutional Empiricism: Quasi-Neutral Principles and Constitutional Truths. North Carolina Law Review, Vol. 82, December 2003, Available at SSRN: or

Timothy Zick (Contact Author)

William & Mary Law School ( email )

South Henry Street
P.O. Box 8795
Williamsburg, VA 23187-8795
United States
757-221-2076 (Phone)

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