However, there would have been evidence if Darwin had disclosed upfront in his theory of the origin of species - as an axiom or postulate - that he takes life as a "given" offering neither a definition of what life "is" nor an explanation of its origin.
It would be much easier to point to that evidence and say that whatever else he might have written or how anyone might have used the theory to advance their sinister theological or political agendas etc. is therefore irrelevant to the theory itself.
If they chose to believe other sources rather than do the research and find out for themselves, I don't see how it would matther what Darwin wrote.
If the people they choose to believe tell them "Darwin said 'A'", and I tell them "No, Darwin said 'B'" they are going to believe that Darwin said 'A', whether he really did or not.
It is why it is so difficult to get a conviction on circumstantial evidence.
And it is the Achilles’ heel of evolution theory – indeed of all historical science theories (anthropology, archeology, etc.)
After all, not every creature that ever lived left a complete record of itself. What does survive is circumstantial evidence (a quantization of the continuum.)
Therefore, to superimpose the finding in the laboratory concerning bacterial evolution onto the paleontological record is to overstate what is knowable.
There are no laboratory experiments which can falsify an alternative explanation for the paleontologists’ discovery in the dig (e.g. God’s special creation, panspermia, Gaia/collective consciousness of the universe.)
And we see the tendency to superimpose, and the inability to falsify a superimposition, in the case at hand because Darwin did not disclose in his theory of the origin of species - as an axiom or postulate - that he takes life as a "given" – that he offers neither a definition of what life "is" nor an explanation of its origin.
Again “the absence of evidence is evidence of absence” is a rational and effective defense. The juror will fill in the blanks as he chooses.
One might conclude that Darwin didn’t say anything so we ought to give him the benefit of the doubt and assume that means he didn’t have a position on such matters. That we cannot assume he had a motive for not mentioning his presuppositions or if he had any.
Another might say, just as rationally, that Darwin intentionally did not mention his presuppositions because most of his peers believed in God and if he had said what he really believed about a warm little pond and that God doesn’t exist, his theory would have been rejected out-of-hand. Which is to say, people tend to be self centered and therefore Darwin’s motive can be presumed to be self-serving.
Another might say based on his theological beliefs that Darwin was wittingly or not involved in a dark, sinister, Satanic plot to snatch away the faith of the weak and young prior to the end of days – that mentioning anti-God presuppositions would have revealed his hand – conversely, by not mentioning it, he would appear as an “angel of light” to those seeking earthy knowledge. Which is to superimpose a particular belief in end times prophecy, and the bloody historical record after his theory was published, onto Darwin as one of the actors, e.g.
And no marvel; for Satan himself is transformed into an angel of light. – 2 Cor 11:4
And many false prophets shall rise, and shall deceive many. – Matthew 24:11