Maxim 5: Loglans increase rationality.
This is New Age SWH, taken now not as a hypothesis to be tested but as a theory to used. The idea is that, since Loglans incorporate logic and logic is at the root of rationality, speaking a Loglan will make for more rationality. The shift from hypothesis to guiding principle is alrady present in much of Whorf at least, so the move is not unprecedented, And, as in Whorf, it functions at several levels, personal, global and political. Sometimes it is just the speaker who becomes more rational; sometimes it is that a world with many Loglan speakers would become a more rational world; sometimes it is that, should Loglan become the language of diplomacy and law, the world would become a more rational (and, hence, peaceful and pleasant) place.
Aside from the problems with SWH as a description of anything, this view also relies on the rather tenuous connection of Loglans with logic and upon the connection of logic with rationality. To be sure, it is rational to accept the conclusion of a valid argument from premises you accept and less rational not to. And logic (in the present sense) provides a direct means for determining that a valid argument is valid. So, it is a useful tool in the pursuit of rationality. Logic (in a slightly extended sense) also usually provides a tool for finding that an invalid argument is not valid, may even – more usefully – suggest both arguments that are like the present one but clearly wrong and also suggest claims that, if they were premises, would make the argument valid but are clearly false. Both of these are useful in countering bad arguments, whether in a debate or in one's own reasoning. But this is not all there is to rationality and for these other part, logic has little to do.
There is, first of all, the issue of those premises from which we draw conclusions. Some of them may, of course, be conclusions from other premises, but most are not in any formal sense. They are the products of experience, and education, and conversation, and thinking in less structured ways, never of formal argumentation. We think they are true and suppose them to all hang together in a consistent whole (logic can say something about this point), but in fact they are rarely examined, even (especially?) by philosophers, the purported paragons of rationality. So, we may rationally move from minor errors to catastrophes in a perfectly rational way. But we are inclined to think that people who hold to beliefs that result in clear conflicts with reality are irrational. If so, then logic has even less to do with rationality, for many such people hold beliefs that follow quite validly from their core beliefs and if these seem to conflict with what other sees as happening, then those others just have misunderstood the real situation (countless contemporary cases will spring to mind).
But even supposing that logic had more to do with rationality than it does, the notion that knowing logic thoroughly makes one more rational could easily be quenched by attending a meeting of the Association for Symbolic Logic. It will be filled with the same political bickering, petty back stabbing, sly thefts and digs as any other academic meeting – not even better disguised. And, of course, there is always the famous 20th century logician who wrote a paper brilliantly demonstrating that substitutional quantification was the proper way to do metatheory – and then spent the rest of his life claiming that the paper had totally demolished the claims of any such metatheory (and, as an added point, he called himself a nominalist).
Since logic (let alone Loglans) does not seem to have anything to do with individual rationality, it seems unlikely that a leaven of Loglanists in the world would raise the level of rationality. The leaven principle does occasionally work, as most revolutions – and maybe some cases of less violent but equally significant social changes – show. But the baking soda or yeast is missing here, and, even if people were more logical, that would not, as noted, necessarily make for a more rational (or otherwise better) world.
Only in the matter of a Loglan as the language of diplomacy, of the framing of laws and treaties and the like, does there appear a chance that something of this maxim might make sense. If the legislation or treaty were written in an unambiguous language, then many of the quibbles that have fed disputes, suits, and wars would be avoided. But the Loglans are only syntactically unambiguous, so this only solves such disputes: whether a condition applies universally or only to the last mentioned case, for example, or (maybe) whether a clause is motivational or regulatory (“a well regulated Militia, being necessary for the security of a free State” or some such). But beyond that, there are the words that fill between the logical connections and there is no guarantee in the Loglans that they are unambiguous. To be sure, the tendency in vocabulary creation has been in that direction since very early on (Brown was rather loose, but computer scientists have long been in control and they constitutionally are not). Single concepts have been divided and subdivided for greater accuracy (although this is not strictly about ambiguity). And one would expect the same and more if the task were given over to lawyers and diplomats. But at least the latter are also notorious for tact, wording an unpleasant claim in a less unpleasant form, and thus for words that are fuzzy (not in the strict logical sense, perhaps). And, in the press of events, a fuzzy term can be brought into two quite different focuses, each favorable to one side and not the other: a tactful demand can be called a polite suggestion, and so on. That is, however much a Loglan might reduce the area of permissible disagreement, it cannot remove most of the main points of contention.
Finally, the obvious needs to be said. Nothing in the Loglans prevents lying or flags it when it occurs. Nothing in the Loglans prevents a word from having a negative, pejorative, dismissive or scurrilous connotation, even if every effort is made to keep such factors out of its definition. So, Loglan discourse can be as loaded as one wants, spreading good will or ill by seemingly factual claims. One might take this to be good news, since it means that the Loglans are actually languages (though it should be noted that, unlike Esperanto, there are no reported cases of Loglans actually being used in these ways, in spite of some tempting situations). So, assuming stooping to invective is irrational, Loglans have no special innoculation against it.