A lot of this advice is ostensibly specific to essays, but I think a lot of it could be easily co-opted for technical writing.
It’s easy to make a statement correct by making it vague. That’s a common flaw in academic writing, for example. If you know nothing at all about an issue, you can’t go wrong by saying that the issue is a complex one, that there are many factors to be considered, that it’s a mistake to take too simplistic a view of it, and so on.
Precision and correctness are like opposing forces. It’s easy to satisfy one if you ignore the other. The converse of vaporous academic writing is the bold, but false, rhetoric of demagogues. Useful writing is bold, but true.
Let’s put them all together. Useful writing tells people something true and important that they didn’t already know, and tells them as unequivocally as possible.
my friend Robert Morris, who has a horror of saying anything dumb. His trick is not to say anything unless he’s sure it’s worth hearing. This makes it hard to get opinions out of him, but when you do, they’re usually right.
As you try to refine the expression of an idea, you adjust the qualification accordingly. Something you’re sure of, you can state baldly with no qualification at all, as I did the four components of useful writing. Whereas points that seem dubious have to be held at arm’s length with perhapses.