A SLIGHT CHILL does run down your spine in the opening few minutes of this touching, disciplined study of Charles Darwin.

The distinguished biologist TH Huxley, played with insidious guile by Toby Jones, visits Darwin (Paul Bettany) in the country and urges him to finally go public with his theory of evolution. In the course of his argument, Huxley explains Darwin’s own idea to him in baby talk.

Oh dear. Is this going to be one of those condescending biopics that talks down to its viewers throughout? Will there be a scene in which some toff declares: “Are you calling my wife a monkey, Mr Darwin, sir?“?

Not at all. Loosely based on Randal Keynes's moving book, Annie's Box,which examined how the death of Darwin's daughter altered the naturalist's attitude towards religion, Creationhas the good sense to focus quite acutely on just one corner of the great man's story.

The film is mainly concerned with the final months of the 20-year gap that separated Darwin's voyages on the Beaglefrom his eventual publication of On the Origin of Species.Presenting Emma Darwin (Jennifer Connelly, Bettany's own wife) as the voice of humane Christianity, Creationfinds its hero driven half-crazy by grief and by the burden of his big idea. The tussle allows the film-makers to grapple with an impressive array of moral and ethical dilemmas.

Jon Amiel, a jobbing British director for several decades, includes a few extravagant sequences of natural decay, which, if a little explicit, do help remind us of the principles that drive the theory.

More awkward (and of dubious historical accuracy) is the schematic divide between Emma’s Unitarian simplicity and Charles’s tortured, erm, Darwinism. The disagreement cannot have been so neatly binary, and lines such as “you’ve killed God” do not make the piece seem any less diagrammatic. The literal depiction of the deceased daughter as a ghost is also a tad unsubtle.

All that noted, Creationdoes a very good job of turning Darwin from a prophet/demigod/monster (delete according to your views) back into a flawed, uncertain human being. Much of the credit for that must go to Bettany, whose fragile charisma seems perfectly appropriate for a troubled scientist.

Okay, Darwin may not have been this particularflawed, uncertain human being, but Bettany's performance is compelling enough to send the attentive viewer back to the source material. That's a worthy achievement.