THE series of columns I’ve been writing lately, floating implausible proposals for an ideologically unstable age, has been a useful way of avoiding the depressing subject of the Trump administration’s first 100 days — because really, in the face of such incompetence and chaos, what is there to say?

But precisely because this administration seems so hopeless, any constructive advice for the Trump White House automatically falls into the category of implausible ideas. So I can continue my ongoing series while also talking about Donald Trump — by proposing, as this week’s unlikely-to-happen proposal, that our president should go out and get himself a brain.

I do not mean a vat-grown cerebral cortex cooked up in some underground anti-aging lab funded by Silicon Valley immortalists … though I gather those may be soon available as well. I mean a brain in the sense that people (unkindly, but not inaccurately) used the term to describe Bill Kristol when he was the aide-de-camp to Vice President Dan Quayle 25 years ago: a person, or better a group of persons, who can tell Trump what specific policies he ought to support.

Because a core weakness of this White House, more devastating (for now) than the pugilistic tweets and permanent swirl of scandal, is the absence of anyone who seems to have thought through how one might translate Trumpism, the populist nationalism on which the president campaigned, into substantive policy on any specific issue except a temporary visa freeze.