The Old Vic’s brilliant revival under director Trevor Nunn of Jerome Lawrence and Robert E. Lee’s 1955 American courtroom drama Inherit the Wind marks the 150th anniversary of the publication of Charles Darwin’s On the Origin of the Species. This seminal scientific work is central to the plot of the play, which concerns the prosecution of a young schoolmaster for breaking a state law against introducing young minds to a concept – evolution – judged to be inimical to the teachings of the Bible.

The story is closely based on a real-life case – dubbed ‘the monkey trial’ by the great journalist H.L. Mencken who chronicled its every twist and turn – heard in Tennessee in 1925. And even as we scoff at the absurd attitudes of those who caused it to happen, dismayed by the blinkered denial of proven scientific fact at its centre, it is instructive, if depressing, to consider that nearly half of present day Americans still believe in the literal truth of a seven-day Creation.

The two celebrated jurists who appeared in ‘the monkey trial’, William Jennings Bryan – a three-times Democratic presidential candidate (failed) – for the prosecution and Clarence Darrow for the defence, both figure, very thinly disguised, in the play as, respectively, Matthew Harrison Brady and Henry Drummond – as does Mencken, as the sharp-dressed, sharply witty E.K Hornbeck (Mark Dexter).

The legal foes are tremendous characters, offering challenging and compelling parts to the fine actors who play them. David Troughton gives us Brady as a pot-bellied, barnstorming, Barnumesque man-of-the-people, glad-handing all whom he meets while shrewdly assessing their usefulness to him. Kevin Spacey’s Drummond – round shouldered, limping and made up to look, bizarrely, like the late Hughie Green – is, by contrast, a man of sharper intellect, a seeker after knowledge rather than the comforts supplied by dogmatic belief and superstition. Each is a champion of truth, as he sees it, however, which at bottom perhaps accounts for the mutual respect that is shown to exist between them.

As in any partly documentary play such as this, there is a constant nagging worry as to whether this or that incident occurred as it is presented or whether it occurred at all. It seemed unlikely in the extreme to me, for instance, that Drummond, prevented by the decent, if biased judge (played by Nicholas Jones) from calling any scientific experts, had instead summoned Brady to the witness box to be quizzed on the Bible. Yet Trevor Nunn assures us in a programme note that this is exactly what happened.

I am still not prepared to believe, though, that the defendant in ‘the monkey trial’ was amorously involved with the local preacher’s daughter, as Sam Phillips’s Bertram Cates is here with Sonya Cassidy’s Rachel Brown, daughter of the hellfire-spouting, near-mad Rev Jeremiah Brown (Ken Bones). Surely this is no more than the introduction of a romantic element without which no fifties play (this one, of course, later famously filmed with Spencer Tracey and Fredric March) would have been deemed complete.

The rhesus monkeys that appear (one per performance) on Trevor Nunn’s hugely populated stage – all Southern life is here! – come from Amazing Animals, near Chipping Norton. Many of us might feel it a privilege rather than an insult to have descended from such lovely of God’s creatures.

Old Vic, until December 20. Tel: 0844 8717628 (www.oldvictheatre.com).