While reading Thomas Malory’s Le Morte D’Arthur, in Chapter 25 of Book 8, I came upon this striking sentence:

Ye shall want no thing that you behoveth

My first parsing of it was wrong. When it was written, the nominative second person plural pronoun was “ye” (as at the start of the sentence), so “you” must be the object of the verb “behoveth”. Also, the ending of the verb shows that it is third person singular, so its subject must be “thing (that)”. Changing the word order to a more modern form makes it clearer: “Ye shall want no thing that behoveth you.”

The verb “behove” (correctly pronounced “behoove”) is defined by my Chambers dictionary as “to be fit, right, or necessary”; it can (as here) be a transitive verb. So the sentence means “Ye shall want no thing that is necessary for you”. The best-known occurrence of a derivative word is probably the sentence of Julian of Norwich, used by T. S. Eliot in Four Quartets:

Sin is behovely; but all shall be well, and all shall be well, and all manner of things shall be well

(amazingly optimistic words!)

I fantasised briefly about trying to popularise this word as a mathematical term. We could say, “Continuity behoves differentiability”, or, “For numbers n congruent to 1 or 2 mod 4, being a sum of two squares behoves the existence of a projective plane of order n” (The Bruck–Ryser Theorem).

But I doubt that it will catch on …

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About Peter Cameron

I count all the things that need to be counted.
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9 Responses to Necessity

  1. Jon Awbrey says:

    You can’t always get what you want
    You can’t always get what you want
    You can’t always get what you want
    But if you try sometimes you just might find
    You just might find
    You get what behoveth you

  2. D. Eppstein says:

    Maybe this is obvious, but it’s probably also worth pointing out that here “want” means “go without”, not “desire”.

  3. Jon Awbrey says:

    Synchronicity and ultimately periodic reference being what they are, the subject of necessity in mathematical reasoning came up again recently on the Peirce List, and I blogged a salient quotation from CSP just yesterday.

    My father’s definition “mathematics is the science which draws necessary conclusions” at least implies the truth. Modern logic shows that all necessary inference is really mathematical; and no inference could be necessary if it related to anything more than a hypothesis.

    But the best definition is “mathematics is the science of hypotheses,” or of precise hypotheses. For one important part of the mathematician’s business is to frame his hypothesis and to generalize it. The drawing of conclusions about it is not all.

    Charles S. Peirce, [Logic of Number — Le Fevre] (MS 229), published in Carolyn Eisele (ed., 1976), The New Elements of Mathematics by Charles S. Peirce, vol. 2, 592–595.

  4. Colin Reid says:

    I hadn’t thought of it before, but ‘require’, ‘necessitate’, ‘imply’ and ‘suffice (for)’ all go in the same direction of implication (assuming law of excluded middle). ‘Behove’ goes in the opposite direction.

    However, some Googling suggests that ‘behove’ has been a chiefly impersonal verb for many centuries, probably even in Malory’s time. So saying ‘A behoves B’ where A is a full noun phrase (as opposed to it/that/which etc) would be even more archaic than the usage you quote.

    • Quite a few verbs could be added to the list: “entails” springs to mind. In fact this seems so ingrained that I found it difficult to write “Continuity behoves differentiability”, so strongly did it seem to be the wrong way round.

    • Adam Bohn says:

      I had never heard of the “is necessary for” usage; but “behoves” is still sometimes used in the sense of “is fit/right for” (in fact, I remember my dad telling me once that my behaviour did not behove me).

      There are lots of examples of words which have had similar but different definitions in the past, such as “to doubt” as used in the biblical sense “to fear” (and indeed “to fear” used as “to revere”, as in “God-fearing”); and “to prove,” which once meant “to learn.” I’m not sure if multiple definitions of these were once used simultaneously or not, but I would imagine that any word with two different definitions which could easily be confused will inevitably come to mean one or the other exclusively. (On the other hand, “to prove” also means “to rise” in the context of baking, but this never creates ambiguity, as so there is no reason to stop using it).

      The problem with the “necessary” definition of behoves is that it makes any sentence without context sound absurd, but not quite so absurd that it might not temporarily enter your mind (as opposed to the notion of bread demonstrating logical statements, for example). It is fine in the sentence: “If you want to get in the restaurant, then it behoves you to wear shoes,” but if I compliment you on your shoes by saying that they behove you, then you might at first think I was implying that your existence is conditional on your shoes.

      Having said that, it would be very useful in mathematics. Perhaps we could follow Eliot’s lead by proving “behoveliness and sufficiency” from now on…

  5. Jon Awbrey says:

    I don’t know if he was the first or not, but C.S. Peirce observed that “X if Y” over boolean variables X and Y could be expressed as the exponentiation X^Y.

  6. Jon Awbrey says:

    Webster takes me from behoof (advantage, profit) through OE behōf (profit, need) and hebban (to raise) on to OHG hevan (to lift) and ultimately to Latin capere (to take).

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