Sunday April 5, 2026 - Zoom Meeting - Lucretius Book Review - Starting Book One Line 305

These week we will continue around section 1:305 of Lucretius and explore further the implications of the invisibility of atoms and how we can have confidence in something that is not visible. This week we go over Lucretius' specific examples of how we reach this conclusion by analogy.

EpicureanFriends Side-By-Side Lucretius

Multi-column side-by-side Lucretius text comparison tool featuring Munro, Bailey, Dunster, and Condensed editions.

handbook.epicureanfriends.com

At this meeting Robertbravely attempted to summarize aspects of Philodemus' "On Methods of Inference / On Signs" as to where Philodemus comes down on whether positions can constitute"knowledge" or rise only to "probability."

If i recall correctly Robert thought that Philodemus came down on the side off "probabiiity." I was not able to confirm or deny that.

At this moment I still can't, and firm positions are going to have to wait until we can devote more time to review of that work.

However I don't want to leave the conversation as is without some degree of followup, so here is what Claude says when I asked it to compare the Delacy commentary and the Sedley commentary with the DeLacy translation. I'm going to pursue this much further but here is the summary. Take it for what it is worth, but I will say that the following makes sense to me given my current state of understanding Epicurus.

IX. SUMMARY OF PHILODEMUS' POSITION

Philodemus defends the following set of claims, which together constitute the Epicurean philosophy of knowledge:

1. All perceptions are true in the sense of faithfully presenting the appearance that occurs. Error arises only from additional opinion.
2. Inference from perception, properly conducted, is genuine knowledge — not merely probable. The properly-made analogical inference carries the same epistemic status as perception itself (Frag. 2).
3. The criterion of inconceivability converts inductive inference into claims of necessity. When it is genuinely inconceivable (on the basis of broad empirical observation) that the sign could exist without what it signifies, we have established a necessary connection.
4. Non-contestation (ouk antimarturēsis) is a sufficient condition for truth when combined with explanatory power. A theory that conflicts with no phenomenon and explains what needs explaining is genuinely true (for basic physics), not merely probably true.
5. The elimination method is not independently valid but derives whatever force it has from the prior work of the similarity method. Stoic deduction is epistemically downstream from Epicurean induction.
6. The Stoic pithanon classification is rejected for properly-conducted empirical inference. It may apply to careless or premature inferences; it does not apply to inference conducted with wide and varied observation, correct identification of relevant qualities, and confirmed by non-contestation.
7. Degrees of certainty exist within the class of warranted inferences: some inferences are more secure than others, depending on the uniformity and breadth of the evidence. But the existence of more and less secure inferences does not mean that the more secure ones are merely probable.
8. The limits of knowledge are real: some things (the parity of the stars) are genuinely unknowable; for celestial phenomena, multiple explanations may all be equally acceptable; for basic physics, uniquely determined truth is achievable.

In short, Philodemus' position is a robust empirical foundationalism: the senses give us infallible access to appearances; properly-made inferences from appearances give us genuine, necessary knowledge of the unperceived world. This is neither scepticism (knowledge is impossible) nor rationalism (knowledge requires a priori foundations). It is a demanding empiricism that claims genuine knowledge of atoms, void, and unperceived objects throughout the universe.

Robert I have completed my first review of the full Claude summary, and it appears to me to be excellent. For ease of followup I would appreciate further comments on this topic being made over there so we can keep most of the discussion in the Philodemus subsection:

Thread

Epicurean Canonics Based On Philodemus As Analyzed By Sedley's "On Signs" and DeLacy's "On Methods of Inference"

I have asked ClaudaAI to take the DeLacy translation and commentary, as well as Sedley's essay On Signs, and produce a detailed outline and analysis of the work based on those two authorities. After reviewing the result it looks pretty good to me, and extremely useful.

Given it's length and easier presentation in markdown format than here, I'll link it first (where it is easier to read). The full text follows after the link. Given the duplicate effort in maintaining two copies I will probably…

Cassius

April 6, 2026 at 10:39 AM