The Truth-Teller, an ambitious new play by David Crook, attempts to disassemble a dissembler but its treatise on honesty is too shallow to be affecting.

Jonathon (Tom Radford) is a compulsive liar so addicted to dishonesty he is incapable of telling even the smallest truth. His exasperated girlfriend Mary (Martha Barnett) packs him off to Shane (Gary Cady), a rather shady psychiatrist, and after a couple of lectures about Immanuel Kant’s Critique of Reason, and a brief session of hypnosis, Jonathon’s crippling condition is completely cured. He is now totally incapable of deception and, who would have guessed it? Being unable to hide the truth turns out to have a few drawbacks of its own.

Playwright David Crook explores some interesting ideas about the nature and morality of truth and lies, but instead of dramatizing these concepts he wedges long lectures on the philosophies of Kant and Dietrich Bonhoffer into the clunking script. The endless revelatory speeches are tediously protracted and give a superficial, hollow look at the subject of truth-telling.

The writing and characterisation leave the actors little scope for emotional range, though Martha Barnett manages to maintain an almost perverse sincerity. It’s difficult to see what her sweet-natured Mary sees in Jonathon, whose addiction to his own outrageous lies might be pitiful if he wasn’t such a charmless moron.

There are a few silly gags that raise a titter but, despite his obvious comic timing, Naveed Khan’s turn as a Sri Lankan shopkeeper Sasruthra is little more than an uncomfortable racial stereotype.

I feel a little bad about writing such a scathing review, but I’m just being honest. For a play about veracity, The Truth-Teller feels utterly fake.

- Georgia Blake