Talisse and I have a short bit at Philosophy15 on a new fallacy we’ve been seeing in philosophy. Well, really, it’s not a new phenomenon, we’ve just started noticing it. One reason is that we’ve become particularly interested in how dialectical standards change over extended philosophical work. Here’s the basic setup.
Stage 1: Hold one’s dialectical opponents to a very high standard of scrutiny.  Show that they do not pass that level of scrutiny.
Stage 2: Deduce that the standard of scrutiny is likely too high, and then introduce a new, lower standard.
Stage 3: Show that one’s own view passes the lower standard.
The problem is that in many cases, the other views criticized in Stage 1 would pass the lower standard in Stage 3, just as one’s own view does. But they don’t get mentioned in stage 3. So the argument proceeds as though their being eliminated by the high standards eliminates them full stop.
This strategy we call clearing the decks. It shows up lots in the history of philosophy, and it is particularly noxious when philosophers do metaphilosophy.
The basic rule, we think, that gets broken is a form of the rule that in deliberating between choices, one uses a consistent standard for the ultimate decision. It’s not that one must use the same standard throughout, as we can find that some standards are too strict or lax and need to change them. It’s just that when we make the final decision, we apply the same standard to all eligible options. With clearing the decks, once the standard is lowered, there are more eligible options.  In some ways, it’s a form of argument from double standards.