The Philanthropist, Donmar Warehouse, London

Now he's portraying a philology lecturer in Christopher Hampton's The Philanthropist, a play from 1970 which is receiving a welcome revival at the Donmar Warehouse in David Grindley's sharply etched and highly entertaining production.

As the title suggests, this early work is a clever, witty inversion of Molière's great comedy The Misanthrope. For the hypocritical hothouse of Louis XIV's court, we have the backbiting, bitchy world of modern academe. The insularity of the milieu is satirically underlined by the political backdrop: the assassination of the Prime Minister and the majority of the Cabinet are ludicrously not enough to wrest the attention of the dons and literati from their own self-absorbed concerns.

Hampton's master-stroke is to put at the heart of the play a reverse-image of Molière's Alceste, the man who takes scathing hatred to an extreme. In his place, we have Russell Beale's Philip, a bachelor don who anxiously likes everyone and has to be a philologist because he is incapable of the critical judgements needed to teach literature.

Pitch-perfect in terms of period feel, Grindley's production can't disguise the fact that the piece operates on different levels of achievement. The kind of writer who has been forced to abandon the left wing for tax reasons is lampooned with an almost counter-productive heavy-handedness in the velvet-suited, strenuously "shocking" Braham (Simon Day) whose new novel is about a social worker who sees the light and becomes a merchant banker. Philip's engagement to the beautiful, preeningly malicious young graduate, Celia (a spot-on performance from Anna Madeley) only starts to feel genuine when it begins to unravel horribly.

But Hampton's insight that Philip's liking everybody through terror would wind up leave him as isolated as Alceste, who hates everybody from pride, is brilliantly realised by Russell Beale.

Playing a dumpy, chronically apologetic and indecisive don ("My trouble is, I'm a man of no conviction. At least I think I am"), he is hilarious at the farcical aspects of Philip's plight. Unable to hurt the feelings of a nubile sexpot, he succumbs to her seduction, and I'll never forget his priceless, slightly flattered, intensely panic-stricken look as she musses his hair into an impromptu Rod Stewart look.

Russell Beale is absolutely matchless, though, at portraying characters who kick over all their emotional defences and retain a quiet, matter-of-dignity as they face up to humiliating truths. And so he is here as he projects the terrible loneliness of a don who belatedly realises that if liking people is half the battle, this was, in his case, "the wrong half".