Circumstantial (Indirect) and Direct Evidence / Dogmatism vs Skepticism

I agree with Martin but would add as to this that we must be clear about what "conclusive" means:

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Quote from Martin

We should not wait until the evidence for this is conclusive because it will never be conclusive.

In the law we convict people and put them to death on a regular basis by holding to be conclusive the standard of "beyond a reasonable doubt." And we do so even though we do not "see" them commit crimes directly. We accept that circumstantial evidence is amply sufficient to reach reasonable conclusions, just as we conclude that "atoms" (indivisible particles) exist without seeing or touching them directly.

It would not be reasonable or proper to require "omniscience" as some people seem to want to equate to "conclusive." "Conclusive" should be read to mean that we have sufficient evidence - clear direct and/or circumstantial evidence which is not contradicted by other clear direct or circumstantial evidence - to reach a conclusion beyond a reasonable doubt. Otherwise we create ambiguity and doubt where none should exist.

In those cases where the direct and circumstantial evidence is insufficient to support support a clear conclusion, we "wait." In cases where clear evidence supports multiple possibilities, we do not arbitrarily choose among them but hold them all to be possible.

But we never 'wait" on the grounds that we are not omniscient or based purely on speculation that "anything is possible" or "some other undiscovered evidence *may* exist." We wait only when we have clear reason to do so, and pure speculation or insistence on "omniscience" is not a clear reason to suspend judgment.

In the podcast we will eventually address this issue of "when is it appropriate to say that we know something" by covering Philodemus' "On Signs / On Methods of Inference." We've also already covered these issues in past discussions of Lucretius Book 4 as to the possibility of knowledge and in discussions of Principal Doctrines 23 and 24.

The Lucretius material is most focused starting around Book 4 line 462 -

Again, if any one thinks that nothing is known, he knows not whether that can be known either, since he admits that he knows nothing. Against him then I will refrain from joining issue, who plants himself with his head in the place of his feet. And yet were I to grant that he knows this too, yet I would ask this one question; since he has never before seen any truth in things, whence does he know what is knowing, and not knowing each in turn, what thing has begotten the concept of the true and the false, what thing has proved that the doubtful differs from the certain?

but for many lines before and after that the topic is the same -- we understand that illusions can occur but nevertheless we learn to use the senses properly and we still reach firm conclusions after we process multiple observations.

The words 'conclusive" and "conclusion" are key. Socrates alleged that he did not conclude anything except that he could not conclude anything. This conclusion is self-contradictory BS and Epicurus concludes firmly that it must be rejected. In doing so, Epicurus is illustrating that conclusions are possible even though we are not omniscient.

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I modified the title of the thread just slightly to make clear that there are two kinds of evidence that must be consided in evaluating when we can be dogmatic and reach a conclusion and when we cannot.

Direct evidence is direct observation. We determine honey is sweet and snow is white by direct observation through the senses.

Indirect evidence is also called circumstantial evidence. We conclude that atoms (indivisible particles) exist even though we cannot see or touch them directly because the things we do observe directly (the circumstances or indirect observation) are seen to operate consistently with atoms being the cause of the regularity of what we do see. We therefore know atoms exist only circumstantially, but we are nevertheless sure that they do exist. We do not "wait" for more information or hold open the possibility that "maybe rather than atoms there are supernatural forces we have not yet discovered" because to do so would be sheer speculation. The decision to reject sheer speculation is at the heart of what it means to be Epicurean.

You can easily be a Muslim, Christian, or Jew and understand that eating too much ice cream will bring pain that outweighs the immediate pleasure. You cannot easily be a Muslim, Christian, or Jew and reject "faith" - which is regularly understood to be belief without "evidence."

And as Joshua brought up in our recent conversation about reasoning in Lucretius, this issue is why it is important to be able to do more than give a blank stare when the Stoics or Thomas Aquinas or others start insisting that there is a supernatural realm based on "arguments from design" or "ontological arguments" that amount to assertions based purely on speculation or word games. It is essential to have a clear understanding of when it is proper to consider something as "conclusive" and when it is not.

It is sound to conclude that atoms exist. It is not sound to conclude that supernatural forces exist.

Also don't forget the inherent ridiculousness of trying to reason with someone who rejects evidence-based reasoning. They are speaking nonsense and once they start down that road Lucretius says the ultimate response is not to engage with them further:

Against him then I will refrain from joining issue, who plants himself with his head in the place of his feet.

In both the question of knowledge and of determinism you can point out to the other person that their position is self-contradictory, but ultimately in most cases they won't care about self-contradiction since they don't care about evidence.