Cato the Elder had his famous “Carthago delenda est”; Newton had “hypotheses non fingo”, Laplace had “Je n’avais pas besoin de cette hypothese-la” (not Latin, I know). I seem to remember that there was some other historical figure (19th century philosopher, maybe?) that was associated with a pithy Latin phrase that meant something like ‘I have not seen your evidence’ or ‘show me your evidence’ or ‘claim without evidence is [something]’. Does this ring any bells? I realize it’s not much to go on.
Not sure about the examples you cite, but ‘Cui bono’ counters a lot of alleged evidence.
There’s also the tried and tested one which scientists use against the tragic set of individuals who are convinced by the ‘Creationist’ condition: “absence of evidence is not evidence of absence”.
And then there’s: “What is asserted without proof (evidence, reason), may (can) be denied (dismissed) without proof (evidence, reason).”
Let’s see:
Bush managed to benefit from 9/11, so he caused it.
FDR managed to benefit from Pearl Harbor, so he caused it.
I managed to benefit from my conception, so … dammit my brain just melted.
Yep, flawless reasoning.
It can be. It depends on the circumstance. For example, is there a gold bar lying in your lap right now? There’s very likely no evidence of any gold bars.
This actually comes close to answering the question that was posed.
Not 19th Century, but how about “Ostende mihi pecuniam” --Hrodric Tidwellus? You may be remembering it from the documentary “Jerry Maguire”.