Discussing his book 'The Evolution of Everything: How Ideas Emerge' at the Chalke Valley History Festival, science writer Matt Ridley said both had "become ubiquitous, monopolistic and eventually intolerant" at the Daily Mail sponsored event.
"The notion that the Roman Empire was ripe for a monopoly religion to take it over at around the time of Christ is probably an inevitable one.
"There were a huge number of different religions in the Empire and the chances were that one of them would 'do a Starbucks', become ubiquitous, monopolistic and eventually intolerant and kick the other ones out.'
He claims in the first century AD, other figures were better known and followed than Jesus but their philosophies fell by the wayside for Christianity.