Jonathan Bernier has made a nice analogy between illnesses and historical events – more specifically between tumors and the crucifixion. His point is that doctors, like historians, deal indirectly with underlying causes, at least in the first instance. Eventually a team of surgeons may make incisions and see for themselves what lies at the heart of someone’s symptoms. But at the start, what a doctor has to go on are symptoms, and they must deduce what the most likely cause of those symptoms are. Depending on what the symptoms are, they may or may not even recommend an operation to look for something deeper.
In much the same way, texts are symptoms. The academic reader using certain kinds of approaches will ask what the texts are symptoms of. All texts have human creativity as a cause, and so the mere fact that they are dealing with literature (despite what some people like Thomas Brodie have said) do not tell you anything about what other underlying causes there may be, perhaps including pressures in the time of the author, memories or stories stemming from historical events, and so on.Much like doctors, and much like those reconstructing the history of life on this planet, historians offer their professional opinion. There is little that one can say to persuade someone who insists that a different diagnosis is preferable – that the pain is due to unspecified “toxins” in the environment that have been absorbed, that the sequence of organisms in the fossil record reflect separate creations by God, that the stories about Jesus being crucified exist because someone felt like inventing a crucified messiah.
Sometimes there is no way to prove who is right to someone who chooses to dogmatically believe otherwise, and sometimes the only proof comes when someone has died as a result of failing to take seriously what their doctors have said. But sometimes doctors are wrong, and there are those who will happily use that as an excuse to ignore medical advice, even though it can be shown that expert diagnoses are more often right than wrong.