Egalitarian schemes, in short, often have great inflationary effect but little actual egalitarian effect. They can amount to mere exercises in mutual make-believe. You can pretend all you want that all the children in Lake Wobegon are above average. People who wish it were true may even go along with the pretense. But of course, it isn’t true, and deep down everybody knows it isn’t true. Hence even many who do pretend to believe it will act otherwise. There will be a lot of pious chatter about how special all the children are, but no one will take the chatter very seriously and everyone will in practice treat the children differently according to their actual, differing abilities.
Now, speaking of egalitarian pretense, consider the idea of “marriage equality,” which Justice Anthony Kennedy pretends to have stumbled upon somewhere in the U.S. Constitution on a Friday morning last June, with (so far) about 42% of the U.S. population going along with the gag. Depending on the political needs of the moment, the proponents of “marriage equality” have also often pretended that their arguments wouldn’t support polygamy, incestuous marriage, you name it.
But everyone knows this isn’t true. For, contrary to some further pretense from the “marriage equality” crowd, the point about the implications of “marriage equality” has nothing to do with making a fallacious slippery slope inference, but rather with making a perfectly valid reductio ad absurdum inference. A slippery slope fallacy fundamentally involves making a causal claim to the effect that A will lead to B, where there is at best a contingent connection between A and B and where no specific causal path from the one to the other has been established. A reductio ad absurdum argument, by contrast, involves making a logical claim about the entailment relations between propositions. In the present case, the idea is that if you not only remove heterosexuality and even fidelity from the essence of marriage, but in general treat the institution as essentially a matter of current social convention and legal stipulation rather than something grounded in nature, then in principle there is no limit to what might be counted as a “marriage.”