FINALHLS.DOC 12/03/99 – 10:19 AM501COMMENTARIESTHE LAW OF THE HORSE:WHAT CYBERLAW MIGHT TEACHLawrence Lessig∗INTRODUCTIONA few years ago, at a conference on the “Law of Cyberspace” held atthe University of Chicago, Judge Frank Easterbrook told the assembledlisteners, a room packed with “cyberlaw” devotees (and worse), that therewas no more a “law of cyberspace” than there was a “Law of the Horse”;1that the effort to speak as if there were such a law would just muddlerather than clarify; and that legal academics (“dilettantes”) should juststand aside as judges and lawyers and technologists worked through thequotidian problems that this souped-up telephone would present. “Gohome,” in effect, was Judge Easterbrook’s welcome.As is often the case when my then-colleague speaks, the intervention,though brilliant, produced an awkward silence, some polite applause, andthen quick passage to the next speaker. It was an interesting thought —that this conference was as significant as a conference on the law of thehorse. (An anxious student sitting behind me whispered that he had neverheard of the “law of the horse.”) But it did not seem a very helpfulthought, two hours into this day-long conference. So marked as unhelp-ful, it was quickly put away. Talk shifted in the balance of the day, and inthe balance of the contributions, to the idea that either the law of thehorse was significant after all, or the law of cyberspace was somethingmore.–––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––∗ Jack N. and Lillian R. Berkman Professor for Entrepreneurial Legal Studies, Harvard LawSchool. An earlier draft of this article was posted at the Stanford Technology Law Review,<http://stlr.stanford.edu>. This draft is a substantial revision of that earlier version. Thanks to EdwardFelten, Deepak Gupta, David Johnson, Larry Kramer, Tracey Meares, Andrew Shapiro, Steve Shapiro,Polk Wagner, and Jonathan Zittrain for helpful discussions on an earlier draft of this essay. Thanksalso to the Stanford and Chicago Legal Theory Workshops. Research assistance, much of it extraordi-nary, was provided by Karen King and James Staihar, and on an earlier draft by Timothy Wu. I ex-pand many of the arguments developed here in a book published this month, CODE AND OTHERLAWS OF CYBERSPACE (1999).1See Frank H. Easterbrook, Cyberspace and the Law of the Horse, 1996 U. CHI. LEGAL F. 207.The reference is to an argument by Gerhard Casper, who, when he was dean of the University of Chi-cago Law School, boasted that the law school did not offer a course in “The Law of the Horse.” Id. at207 (internal quotation marks omitted). The phrase originally comes from Karl Llewellyn, who con-trasted the U.C.C. with the “rules for idiosyncratic transactions between amateurs.” Id. at 214.FINALHLS.DOC 12/03/99 – 10:19 AM502 HARVARD LAW REVIEW [Vol. 113:501Some of us, however, could not leave the question behind. I am one ofthat some. I confess that I’ve spent too much time thinking about justwhat it is that a law of cyberspace could teach. This essay is an introduc-tion to an answer.2Easterbrook’s concern is a fair one. Courses in law school, Easterbrookargued, “should be limited to subjects that could illuminate the entirelaw.”3 “[T]he best way to learn the law applicable to specialized endeavors,”he argued, “is to study general rules.”4 This “the law of cyberspace,” con-ceived of as torts in cyberspace, contracts in cyberspace, property in cy-berspace, etc., was not.My claim is to the contrary. I agree that our aim should be coursesthat “illuminate the entire law,” but unlike Easterbrook, I believe thatthere is an important general point that comes from thinking in particularabout how law and cyberspace connect.This general point is about the limits on law as a regulator and aboutthe techniques for escaping those limits. This escape, both in real spaceand in cyberspace,5 comes from recognizing the collection of tools that asociety has at hand for affecting constraints upon behavior. Law in its tra-ditional sense — an order backed by a threat directed at primary behavior6— is just one of these tools. The general point is that law can affect theseother tools — that they constrain behavior themselves, and can function astools of the law. The choice among tools obviously depends upon theirefficacy. But importantly, the choice will also raise a question about val-ues. By working through these examples of law interacting with cyber-space, we will throw into relief a set of general questions about law’s regu-lation outside of cyberspace.I do not argue that any specialized area of law would produce the sameinsight. I am not defending the law of the horse. My claim is specific tocyberspace. We see something when we think about the regulation of cy-berspace that other areas would not show us.My essay moves in three parts. I begin with two examples that areparadigms of the problem of regulation in cyberspace. They will then sug-gest a particular approach to the question of regulation generally. In thebalance of Part I, I sketch a model of this general approach.In Part II, I apply this general approach to a wider range of examples.It is in the details of these examples that general lessons will be found.–––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––2I have developed elsewhere a complete account of this answer, or as complete as my account canbe. See LAWRENCE LESSIG, CODE AND OTHER LAWS OF CYBERSPACE (1999).3Easterbrook, supra note 1, at 207.4Id.5I have discussed in considerable detail the idea that one is always in real space while in cyberspaceor, alternatively, that cyberspace is not a separate place. See Lawrence Lessig, The Zones of Cyberspace,48 STAN. L. REV. 1403, 1403 (1996).6See, e.g., H.L.A. HART, THE CONCEPT OF LAW 6–7, 18–25 (2d ed. 1994).FINALHLS.DOC 12/03/99 – 10:19 AM1999] WHAT CYBERLAW MIGHT TEACH 503These lessons reach beyond the domain of cyberspace. They are lessonsfor law generally, though the