Silence does not equal denial or affirmation.
If your purpose is to write an accurate and detailed biography of someone then you would not leave important information out unless there was no real evidence that it happened to begin with. If one biographer left the claim out one might easily suspect bias on their part. But all of them? And Taney himself?
You would have us believe you can read Taney's mind now? He may have felt it more politically expedient not to mention it in his memoirs. That does not prove it did not happen. Did Churchill mention Ultra in his memoirs? Yet Ultra existed.
I have read it. I'm still waiting for you to answer my question as to why not a single biographer every included the claim in any of their works. Not even Taney himself in his autobiography. Are you going to continue to ignore the question?
Taney chose not to mention it in his memoirs. As to the biographers, they were unaware that multiple others had mentioned Taney discussed it with them. Taney is not even the only source. Lincoln's secret service bodyguard as well as his personal secretary both said Lincoln signed the arrest warrant. Why would they all say that if it had not happened?
It does indicate lack of proof. Google "Was Abraham Lincoln Jewish?" You're going to find a few websites that will claim definitively that he was. Yet none of his biographers include that claim in any of their works. So if silence does not equal denial or affirmation then are you saying there is a chance that he was? Or does it mean that the biographers examined the 'evidence' and determined that it wasn't credible?
He may have felt it more politically expedient not to mention it in his memoirs.
You would have us believe that you can read Taney's mind now?
As to the biographers, they were unaware that multiple others had mentioned Taney discussed it with them.
Unaware of the Ward Lamon memo? Unaware of Taney's conversation with people that they recorded in the 1860's? How inept would you have us believe they are?