'If need be' somehow sounds so wrong to me, no matter how many times I hear it from no matter how many smart persons. In casual contexts, it sounds like false sophistication, yet in serious contexts, it sounds like a lapse of standards. Weird.
I see it as a contraction of "if there should be a need." It seems natural and efficient. I have no problems with it and use "if need be" often in speech and writing, both casual and formal. Get used to it. It's been around for awhile, peaking near the turn of the 20th century. Ngram.
You might be right there. I still don't like it. It sounds most like an attempt at double-subjunctive, if there exist such a thing. A much more natural way to do contraction: if needed.
I grew up with if need be – doesn't get much more natural than that.
tromboniator said
I grew up with if need be – doesn't get much more natural than that.
I've been cogitating on this, and it seems to me that, especially in order texts, I've read if needs be, needs plural rather than need singular. In my mind, that translates into "if there are such needs as require a particular action, then".
As I find increasingly often, my grey matter is full of crap. The singular form seems to be far more popular at all times, and seems to have preceded the plural form. I find it curious that the phrase enjoyed popularity three centuries ago, and one century ago, being much less popular today and two centuries agp. Not the slightest idea why that may be.
And if I may beg your leave, I need to take a brain laxative. Mayhaps a single malt will do?