# Certainty and Knowledge

**URL:** https://discuss.criticalfallibilism.com/t/certainty-and-knowledge/2045
**Category:** Elliot Temple
**Tags:** bot, curiosity-blog
**Created:** [April 27, 2025, 4:53pm UTC](https://discuss.criticalfallibilism.com/t/certainty-and-knowledge/2045 "2025-04-27T16:53:55Z")
**Posts on this page:** 1
**Showing post:** 26

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### Author: ![Elliot](https://discuss.criticalfallibilism.com/user_avatar/discuss.criticalfallibilism.com/elliot/32/14_2.png) [@Elliot](https://discuss.criticalfallibilism.com/u/Elliot)
#### Post date: [May 14, 2025, 4:14am UTC](https://discuss.criticalfallibilism.com/t/certainty-and-knowledge/2045/26 "2025-05-14T04:14:22Z")

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You’re again using terminology, like “doubt”, vaguely and/or for more than one meaning. I think that’s one of the main issues making this discussion difficult.

> Some key disagreements would be that Popper is a rationalist.

You’ve multiple times accused Popper of stuff without evidence. Instead of listening to Popperians like me about what Popper’s positions are, or using quotes, you make false assertions about his positions.

Note that this again also depends on keeping definitions straight. I mean that Popper is not a “rationalist” by the Objectivist definition. He is a “rationalist” if it’s defined as being in favor of rationality, but so was Rand. Both are standard dictionary definitions.

Here’s Popper near the beginning of _On the Sources of Knowledge and of Ignorance_, the introductory chapter of his book _Conjectures and Refutations_:

> In this lecture I shall try to show of the two schools of empiricism and rationalism that their differences are much smaller than their similarities, and that both are mistaken.

Where did you get your information that Popper is a rationalist?

> [@actually\_thinking](#):
>
> Treating them as provisional, tentative or optional results in a **category error**.

I didn’t say “optional” and “optional” is not a synonym for provisional or tentative. Both “provisional” and “tentative” have multiple definitions, and I’m concerned that this is more terminology confusion.

> Rand claims that omniscience is not needed to be certain about objective facts of reality. Popper claims that nonomniscience precludes certainty.

Again you’re being imprecise with definitions. You’re using a word two different ways in succession. I’ll rewrite it more clearly:

> Rand claims that omniscience is not needed to be **contextually** certain about objective facts of reality. Popper claims that nonomniscience precludes **non-contextual** certainty.

I don’t know how to resolve these issues, let alone cover new topics like foundations, given this sort of imprecision.

I’m guessing the underlying issue is basically that someone told you that Popper was a skeptic, and you believed them without reading Popper. (By “told” I include reading it somewhere.) That’s what I think issues like certainty and doubt are primarily about: whether we can actually achieve (real, good, usable) knowledge.

PS If you want an organized debate with me, see [Debate Policy · Elliot Temple](https://www.elliottemple.com/debate-policy) and [Request a Debate](https://discuss.criticalfallibilism.com/t/request-a-debate/1946). I don’t think it’s a good idea currently, but I do want people to be aware of my policy in case they think they should use it.

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