Absence of evidence IS evidence of absence

I think that, within clearly defined constraints, absence of evidence can be evidence of absence. It man be weak evidence, or it may be strong evidence.If you define a search target, and define a search area - Doing a rigorous search of that area, and not finding that target in that area, would surely be evidence that the target does not exist in that area. This is not to say that a differently defined target does not exist in that area, or that a same defined target does not exist in a different area.As I have followed this topics discussion, that seems to be (at least generally) DNA's line of reasoning.Moose

quote:

---

I agree that that's a valid and reasonable method, but you'll have to show me where DNA said that. Especially the part about defined search areas.

---

I reviewed through parts of the topic, and I think there are at least hints of DNA's touching on it. His rather muddled writting style certainly doesn't help things. I think part of the situation was, that you were reading his posts with the "find him wrong" filter engaged, while I was reading them with the "find him right" filter engaged.Anyhow, I find that the "car keys in the kitchen" discussion may illustrate the situation. I believe it started at Marks message 36.I must find some irony in that it seems that it took until my message 76, to come to a clear, concise statement on it all. And I didn't even get a "Post of the Month" out of it. Moose

quote:

---

If you are looking for something (A) in a well-defined search space and you know that you have covered 100% of that space without
finding (A) then the absence of (A) has been shown.

---

You don't say such, but the above assumes that the nature of (A) is also well defined.Regardless, is not the absence of any evidence of (A) being in the well defined search area, indeed the evidence of (A)'s absence in that area?Moose

In the context of this forum, the "absence of evidence..." theme comes up (mostly, as I see it) in two areas:1) The existence of God.Here we suffer from trouble defining the nature of the search object. The search area has a simular problem. You could define it as some finite area, but the true area needing to be searched seems to be the entire universe (and beyond?). Conclusion: Absence of evidence is not evidence of absence.2) The existence of transitional fossils.I think we can pretty well define the nature of the search object (although the creationist side might disagree). We can also pretty well define the search area, although it would be pretty vast, with most of it buried in the earth.The catch for fossils, is that many critical juncture transitional fossils may never have been preserved in the first place, or may have been destroyed though the recycling processes of geological activity.Of course we can never know for sure, but a given transitional fossil may truly not exist, despite the fact that the life form did exist. Thus we may indeed have an absolute absence of evidence - but while this might be an evidence for the absence of the fossil, it isn't an evidence for the absence of the life form having existed.Boy, my best babble in a long time,Moose