That's not an argumentum ad ignorantiam. If there is no evidence for the existence of souls it is only logical to assume that they don't exist.
And none of this should be considered to disprove the existence of the soul or afterlife, but rather that such explanations of death shouldn't and needn't come at the expense of science, logic, and reason.
That isn't a logical conclusion either, because you cannot prove souls do not exist, nor be certain beyond a reasonable doubt of that fact. We can accurately state they probably do not based on the preponderance of evidence and Occam's Razor. To reject the possibility of their existence outright is no more rational than to play god of the gaps.
I don't agree. There was evidence for the earth being a round, many pointed it out but it was assumed to be false because of personal beliefs and an emotional response.
For souls out the afterlife there is no reasonable evidence at all. Just personal experiences that can't be reproduced or explained logically, like near death experiences simply being hallucinations caused by a dying brain.
You are trying to shift the burden of proof.
Historically speaking, there have been multiple instances of wrong assumptions based on a lack of information. There was in fact a period of time well and prior to adequate understanding of geometry that people believed the world to be flat.
I might have criticisms of @Saurex
in regards to the improper implementation of logic and failure to understand principles of logic, but I don't assume I myself have all the answers when there is so much more to learn. I just don't conjure them up from gaps in our understanding and pretend to know, but instead would rather admit I know nothing to the effect and correct incorrect assumptions based in a lack of knowledge of medical science.
This is why I am an atheist, because I believe it is unlikely their is a god, and know I cannot truly know one to be real. Thus it is more practical to live under the assumption that one does not exist, but this does not reasonably disprove the existence of some form of deity, afterlife, soul, etc. This merely rejects them as improbable rather than wholly impossible, and seeks rational explanations for phenomena before assuming them to be divine or spiritual in nature. The "gotcha" brand of atheist is ironic in its failure to understand the limitations of scientific methodology in exploring the metaphysical by its untestable nature, and that the burden of proof naturally exists for absolute counter arguments against the metaphysical being at all possible.
While I do feel @Saurex
is trying to shift the burden of proof, in this case there is a burden of proof required to make the absolute statement that souls do not exist. One that cannot stand on assumption alone. Such an absolute claim must be absolutely proven, and no human is capable of proving such a claim for either camp of this argument. Rather, I would aim to debunk poor arguments for or against the metaphysical that demonstrate unhealthy failings of reason.
The absence of counter evidence of the soul is no proof of the souls existence, but the absence of evidence to the soul existing cannot prove it does not exist. While probability can be determined, absolute certainty cannot.