In fact you can lodge an appeal based on facts if you think that the judge missed or misinterpreted facts, gave them the wrong weighting or generally used established facts to come to a conclusion that was perverse.
The Court of Appeal did just that in the case of Russell Bragg. He formed a company with Graeme Grant but the two fell out and attempted to reach a deal whereby Grant would sell Bragg his half of the company.
Grant claimed that a deal had been reached at a price of £346,760. Bragg disagreed, but the High Court ruled early last year that two emails constituted a contract for the sale of the shares at that price.
The emails were two of six sent between Grant and Christopher Jenkins, who had drawn up the original share agreement and acted as agents for both men in the negotiations.
Last October the Court of Appeal overturned that ruling in a decision which said that the High Court's treatment of the facts of the case was wrong.
Lord Neuberger said in the ruling that Edward Bartley Jones QC, sitting as a deputy High Court judge, should not have ignored the second, third, fourth and fifth emails in the series and should not have construed a contract out of the first and sixth.
Those intervening emails undermined Grant's claim that a contract for the share sale existed, the Court of Appeal said.
"I have reached the clear conclusion that the judge was wrong to find that there was a binding contract arising from the acceptance in the sixth email of the offer in the first email; I am bound to say that I think he went wrong by just ignoring the intermediate four emails," said Lord Neuberger.
So when can you challenge a court's findings on the facts? Well, one thing to be clear about is that you can't re-hear the evidence and try to overturn a judge's ruling on the ins and outs of what actually happened. Nor can you introduce factual evidence that was available at the time of the first trial.
So if you feel that a judge hasn't properly considered all the evidence or has given undue weight to some evidence and failed to consider other facts, then that might be grounds for appeal.
This is still an unusual route, though, because judges tend to be very good at making sure they properly consider all the facts and make it clear that they have done so.
As always, litigants should be careful about going to court, doubly so when the case demands that a higher court overturn a ruling on facts. They should think: what are their chances of winning the argument? And even if they win the argument, will this bring them the result they desire?
Appeals can turn on facts, then, but that's no reason to launch one.
By Iain Connor, a partner with Pinsent Masons, the law firm behind OUT-LAW.COM.
Editor's note: We reported on the initial ruling in this case last February. The Court of Appeal's ruling of last October only came to our attention this week when we spoke to Russell Bragg, the successful appellant.