Dave relayed to me a story a couple days ago, a story originally told to him with the moral "why engineers hate law school." The professor comes into class, passes out the day's case, and takes the class through a long and detailed exegesis, putting together fact after fact and precedent after precedent to demonstrate why a particular piece of case law applies to another class of cases. The class goes home exhausted but enthused, marvelling at how straightforward and clean the legal process can be, starting to understand how the law proceeds, reasoning carefully through each step of a question and resolving it with the benefit of the evidence. The next day, the professor comes into class, passes out the exact same case, and proceeds to repeat the exercise, putting together a second ironclad argument to show that the piece of case law is entirely inapplicable. The point is that although engineers are seduced by the logical reasoning and apparent rigor of the legal process, they aren't so well-prepared to deal with the law's contradictions and its willingness to decide questions in demolition-derby fashion, seeing which of two arguments holds together better after repeated high-speed collisions. If you go into law expecting each datum to support one side or the other and looking for consistency, you're being set up for a massive disappointment.

I mention this in the context of the recent $145 billion verdict against the tobacco companies. As noted in most coverage of the trial, the long-time defense of the companies has recently started to fall apart. That defense took the following form: smoking isn't harmful and there's no evidence linking smoking to cancer and other diseases, so we're certainly not engaged in knowingly selling dangerous products. Besides which, smoking is harmful and everyone has known this forever, so people who smoke do so in full awarensss of the health consequences. We didn't do anything to you, and besides, it's your own fault. Self-contradictory, sure, but let's look at the counter-claim: smoking is incredibly harmful and you've known this for years and deliberately been selling a product that kills its users. But smoking hasn't really been known to be harmful, and we certainly had no idea it was so dangerous when we started smoking or we'd never have taken it up. But now it's too late, and you owe us lots of money since nobody knew what everybody knew.

To recap, public knowledge that smoking kills supports the tobacco companies (because people who smoke know the risks) and it supports the plantiffs (because the tobacco companies know the risks of the products they sell). Further, public ignorance of these risks supports the tobacco companies (how were they to know cigarettes were so dangerous) and it supports the plantiffs (how were they to know cigarettes were so dangerous). Part of this whole rhetorical mess is just that people have been playing both sides of the Jesuitical street for years and are now reaping what they have sown -- it's hard for the tobacco companies to run from years of publicly denying the health risks of smoking, but history of Surgeon General's warnings are a piece of inconvenient history for government lawsuits against the tobacco industry. It can be very hard to back away from your past arguments -- even if you don't subscribe to them any more -- just because whatever case law you've built up on your side depends on these arguments and trying to switch horses in midstream is a legally dicey strategy.

More to the point, we are holding the law to alien standards if we ask that each piece of data weigh in for one side and one side only. Each fact, each relevant piece of evidence, supports certain lines of reasoning and argues against other lines, emphasizes some factors and mitigates others, and there is no particular reason that the arguments it supports should belong exclusively to one side of a case. Cases wind up looking riotously contradictory because of the selecive filtering each side's briefs peform. Within a brief, it's quite reasonable put arguments in dilemma form: if the evidence is thusly, we are in the right because of so-and-so, but if the evidence instead says this other thing, we are still in the right because of so-and-so other reason. This is just a reasonable covering of all bases. And in comparing opposing briefs on a topic, each side will "conveniently" mention those aspects of a detail which supports their side while omitting those aspects which help the other side. This isn't strange or bizarre at all. Evidence that the defendant was in a highly emotional state may suggest that he was sufficiently bothered by the dispute to kill over it, but it also suggests that anything he did wasn't premeditated. But you'll never hear a trial lawyer stating both these implications in the same breath, for the reason that at trial, lawyers are advocates. It's the judge and jury's job to perform the counterbalancing. And once they've made thet balance and reached a decision, however, narrowly, well, then they're back in the position of trying to make that contested decision appear inevitable and incotrovertible. Think of Brown vs. Board of Education: that unanimous decision was, in part, a way for the Supreme Court to abrubptly reverse course without looking confused and legally shaky.

The recent case in which this whole playing-off-of-opposites has come up time and time again is the Microsoft case. Both sides are "guilty" of this selective amnesia, of this trying to have it both ways at once. High prices for Windows are evidence of monopoly power, but low prices for Internet Explorer are evidence of strongarm tactics to preserve that monopoly. Or is it that the high prices indicate that Microsoft is behaving like a normal business in trying to make money and that the low prices are evidence of intense competition in the browser arena? Windows and IE are too intertwined to break apart, but Microsoft used this tight integration to batter its competitors? Or is it that they're sufficiently separate to split the company up, because Microsoft was a good citizen and maintained a Chinese wall between its divisions? Netscape was a threat, wasn't a threat, and Microsoft killed it off, or didn't kill it off, and this means that IE was an inferior product or a superior one, all of which supports whose case, exactly? The Microsoft case would be a classic example of everyone involved playing off both sides against the middle, if only there were a middle available to point to.

My overall point is that courts of law are actually not a great place to go looking for intellectual consistency, nor should they necessarily be. Dave also pointed out the remarkable extent to which the law changes across the centuries, however much it may seem fixed and stable at any point in time. Law has to be prepared to give and take with the flow of society and custom and to make graceful retreats here and there. The gross inconsistency that the legal process engenders at trial is actually evidence of a well-functioning system, one that has room in it for contradictions and actually encourages differnces of opinion, is willing to listen to alternative points of view. A courtroom in which the accepted legal value of each datum of evidence is agreed to by all sides is a kangaroo courtroom: it's generally only at show trials that prosecution and defense agree on the relevant legal precedent. If you want to see a legal system functioning with fewer blatant contradictions, in which the participants adhere more carefully to a shared set of assumptions and interpetations, in which the meaning of evidence is crystal-clear -- well, then the burden falls upon you to distinguish your legal system from that of Stalinist Russia, where the courts never had any trouble interpreting evidence and arguing over precedent. The evidence always indicated guilt of treason, punishable by death or by exile, clearest thing in the world.