'Of course Gladstone was 20 times cleverer than you,' said my husband. 'Much more, most likely. Why should anyone think different?'
'"Differently", darling. Anyway, they don't mind my saying "cleverer than you". It's "cleverer than me" they don't like.' My husband is easily defeated and went back to his Famous Grouse and his Herwig's Art of Curing Sympathetically. Some chance.
Yes, I had written 'cleverer than me' (5 April), not of conscious purpose, but because the construction must have entered my mental syntax replication machinery. It all hinges on whether than is a conjunction or a preposition. If it can be the latter, I'm in the clear.
It did not take me long to find an eminent ally in Dr Robert Burchfield, the editor of New Fowler's Modern English Usage. As he says, than can be a conjunction in sentences such as 'Diana has better manners than I', where there is an ellipsis at the end, with the implied construction 'than I have'. But he is quite happy to accept a sentence such as 'Diana has better manners than me' where than functions as a preposition and so is followed by the oblique form of the pronoun: me instead of I.
In English, we cannot tell from their form whether nouns or many pronouns following than are nominative or not. But to me – I don't know about Dr Burchfield – the ellipsis argument is not always convincing. It is the same with the subjunctive. People interpret a phrase such as 'whoever he be' as an elliptical form of 'whoever he may be' or 'should be', whereas the subjunctive need not be formed with the auxiliaries may or should; be on its own is the subjunctive form.
Similarly, with than. We do not always think of saying 'bigger than this is'; often we judge two things, one bigger than another. (And would you want to say, 'This thing is bigger than we both'?) In any case, plenty of constructions using than do not imply any ellipsis: 'He climbed no higher than the first floor.'
I admit that the big OED is sniffy about than as a preposition. But the volume that includes than was published in 1919, and has not been revised in this connection. It states that such a usage is 'now considered incorrect', although it wasn't for hundreds of years before. But the clincher in favour of than functioning as a preposition is that everyone accepts the construction 'than whom'. If 'than whom', why not 'than me'?