Does it really matter if you can't believe a word that comes out of a comedian's mouth? There's a lot of talk in comedy about the 'essential truth' behind all the smoke 'n' mirrors, subterfuge and downright lies that stand-ups tell on stage. So, when Bill Burr insists that he's 'actually a liberal' whose material is 'all this shit', you might wish you had several pinchfuls of salt to hand.

The essential truths here, then, are that there's an obesity problem in America, pay inequality is simply wrong, and over-population is a major concern. Through Burr's artistic prism, this means that famous 'fatties' shouldn't be allowed to whine in glossy magazines, women should help foot the bill at dinner, and a cull of the human race needs to begin by sinking all those pointless cruise ships.

If you've seen Burr perform live either in the flesh or on Netflix, then his Edinburgh debut feels a little underpowered (his case for the defence is made early by insisting that he's never done a show in the afternoon). He seems a little baffled by the whole experience, wondering whether the Pleasance Grand has yet to be finished, while his timekeeping is faulty: a shout from the audience that he's got five minutes left leaves him rushing through a final bit on equal pay that falls very flat.

But in his finer moments, you can see perfectly well why he's been touted as one of the top stand-ups in the world. His probe into Kanye's über-inflated ego is really an assault on the historical evils of white men while the material in which he's simultaneously protective and abusive of Caitlin Jenner is potent. These indignant trips into modern celebrity are among the mid-afternoon highlights, but this comedic night owl might have better fortune across the board once darkness descends.

Pleasance Courtyard, until 9 Aug, 3.45pm, 11.40pm, £25.