Winky-face noted and appreciated!

But seriously, by my accounting, every standard of evidence I know includes an element of faith. The only differences between them are (a) what is taken on faith and (b) how credulous that faith is.

Namely, I find faith elements in believing:

• first/second/third-hand reports, even by trained, neutral observers

• expert consensus

• single expert opinion

• by contradiction

• the evidence standards of American civil and criminal trials (note the plural, "standardS". The standards are different between them.)

• induction, including (perhaps) mathematical induction

• "engineering quality" proof

• "mathematician quality" proof

My professional practice as an aircraft mishap investigator is to identify and apply the highest feasible standard from the above list, based on what information is available. "Best practice" in this industry dictates that selection and application of a standard of evidence is a matter of prudential judgement, based on the consequences and probabilities of being wrong, the resources available (evidence, time and $), while being scrupulously open about ones methods.

On historical questions about events of 20 centuries ago, the quality of evidence is not very good. About pretty much everything. What we are left with is Bayesian stuff. Anybody who goes to 0% or 100% draws the raised eyebrow from me. :-)