1. Home
    1. Study Guide
    2. Community Standards
    3. Site Map
    4. Quizzes
    5. Articles On Physics
    6. Articles On Canonics
    7. Articles On Ethics
    8. All Articles
    9. Elli's Blog Posts
    10. Kalosyni's Blog
    11. All Blog Posts
  2. Wiki
    1. Wiki Home
    2. FAQ
    3. Files
    4. Search Assistance
    5. Foundations
    6. Navigation Outlines
    7. Reading List
    8. Key Pages
  3. Forum
    1. Full Forum List
    2. Welcome Threads
    3. Ancient Texts Forum
    4. Physics
    5. Canonics
    6. Ethics
    7. Forum Shortcuts
    8. Forum Navigation Map
    9. Featured
    10. Most Discussed
  4. Latest
    1. New Activity
    2. Latest Threads
    3. Dashboard
    4. Search By Tag
    5. Complete Tag List
  5. Podcast
    1. Lucretius Today Podcast
    2. Episode Guide
    3. Lucretius Today At Youtube
    4. EpicureanFriends Youtube Page
  6. Texts
    1. Overview
    2. Torquatus On Ethics
    3. Velleius On Divinity
    4. Diogenes Laertius
    5. Principal Doctrines
    6. Vatican Collection
    7. Lucretius
    8. Herodotus
    9. Pythocles
    10. Menoeceus
    11. Fragments - Usener Collection
    12. Greek/Latin Help
  7. Gallery
    1. Latest Images
    2. Featured images
    3. Latest Comments
  8. More
    1. Featured Content
    2. Calendar
      1. Upcoming Events List
      2. Zooms - General Info
      3. Fourth Sunday Meet-&-Greet
      4. Sunday Weekly Zoom
      5. Wednesday Zoom Meeting
      6. Twentieth Zoom Meetings
    3. Logbook
    4. EF ToDo List
    5. Link-Database
  • Login
  • Register
  • Search
This Thread
  • Everywhere
  • This Thread
  • This Forum
  • Forum
  • Articles
  • Blog Articles
  • Files
  • Gallery
  • Events
  • Pages
  • Wiki
  • Help
  • FAQ
  • More Options
  1. Home
    1. Study Guide
    2. Community Standards
    3. Site Map
    4. Quizzes
    5. Articles On Physics
    6. Articles On Canonics
    7. Articles On Ethics
    8. All Articles
    9. Elli's Blog Posts
    10. Kalosyni's Blog
    11. All Blog Posts
  2. Wiki
    1. Wiki Home
    2. FAQ
    3. Files
    4. Search Assistance
    5. Foundations
    6. Navigation Outlines
    7. Reading List
    8. Key Pages
  3. Forum
    1. Full Forum List
    2. Welcome Threads
    3. Ancient Texts Forum
    4. Physics
    5. Canonics
    6. Ethics
    7. Forum Shortcuts
    8. Forum Navigation Map
    9. Featured
    10. Most Discussed
  4. Latest
    1. New Activity
    2. Latest Threads
    3. Dashboard
    4. Search By Tag
    5. Complete Tag List
  5. Podcast
    1. Lucretius Today Podcast
    2. Episode Guide
    3. Lucretius Today At Youtube
    4. EpicureanFriends Youtube Page
  6. Texts
    1. Overview
    2. Torquatus On Ethics
    3. Velleius On Divinity
    4. Diogenes Laertius
    5. Principal Doctrines
    6. Vatican Collection
    7. Lucretius
    8. Herodotus
    9. Pythocles
    10. Menoeceus
    11. Fragments - Usener Collection
    12. Greek/Latin Help
  7. Gallery
    1. Latest Images
    2. Featured images
    3. Latest Comments
  8. More
    1. Featured Content
    2. Calendar
      1. Upcoming Events List
      2. Zooms - General Info
      3. Fourth Sunday Meet-&-Greet
      4. Sunday Weekly Zoom
      5. Wednesday Zoom Meeting
      6. Twentieth Zoom Meetings
    3. Logbook
    4. EF ToDo List
    5. Link-Database
  1. Home
    1. Study Guide
    2. Community Standards
    3. Site Map
    4. Quizzes
    5. Articles On Physics
    6. Articles On Canonics
    7. Articles On Ethics
    8. All Articles
    9. Elli's Blog Posts
    10. Kalosyni's Blog
    11. All Blog Posts
  2. Wiki
    1. Wiki Home
    2. FAQ
    3. Files
    4. Search Assistance
    5. Foundations
    6. Navigation Outlines
    7. Reading List
    8. Key Pages
  3. Forum
    1. Full Forum List
    2. Welcome Threads
    3. Ancient Texts Forum
    4. Physics
    5. Canonics
    6. Ethics
    7. Forum Shortcuts
    8. Forum Navigation Map
    9. Featured
    10. Most Discussed
  4. Latest
    1. New Activity
    2. Latest Threads
    3. Dashboard
    4. Search By Tag
    5. Complete Tag List
  5. Podcast
    1. Lucretius Today Podcast
    2. Episode Guide
    3. Lucretius Today At Youtube
    4. EpicureanFriends Youtube Page
  6. Texts
    1. Overview
    2. Torquatus On Ethics
    3. Velleius On Divinity
    4. Diogenes Laertius
    5. Principal Doctrines
    6. Vatican Collection
    7. Lucretius
    8. Herodotus
    9. Pythocles
    10. Menoeceus
    11. Fragments - Usener Collection
    12. Greek/Latin Help
  7. Gallery
    1. Latest Images
    2. Featured images
    3. Latest Comments
  8. More
    1. Featured Content
    2. Calendar
      1. Upcoming Events List
      2. Zooms - General Info
      3. Fourth Sunday Meet-&-Greet
      4. Sunday Weekly Zoom
      5. Wednesday Zoom Meeting
      6. Twentieth Zoom Meetings
    3. Logbook
    4. EF ToDo List
    5. Link-Database
  1. EpicureanFriends - Classical Epicurean Philosophy
  2. Forum
  3. Canonics - The Tests of Truth
  4. Anticipations / Preconceptions / Prolepsis
  • Sidebar
  • Sidebar

Optical Phenomena (Not Necessarily Just Optical "Illusions") And Their Relationship To Prolepsis / Anticipations

  • Cassius
  • October 12, 2026 at 11:45 AM
  • Go to last post
  • Online
    Cassius
    5 - Administrator
    Points
    114,827
    Posts
    15,868
    Quizzes
    9
    Quiz rate
    100.0 %
    • October 12, 2026 at 11:45 AM
    • New
    • #1

    I don't see that we currently have a a thread devoted to the relationship between optical phenomena, like the attached video, and how they relate to anticipations / prolepsis.

    In this example, when you play the video you see pretty clearly the outline of a shape. When you stop the motion the outline largely if not fully disappears.

    I think it's pretty clear from our past discussions that we do not think Epicurus would tell us that the eyes themselves are seeing this shape. So is this a functioning of prolepsis/anticipations that the mind is assembling from repeated viewing of the object the pattern that is created in this example?

    I think optical examples like this can help us clarify our use of the anticipation / prolepisis phenoma along exactly the lines Lucretius discusses in book four of his poem.

    (Note that the music came with the video - not mine - and you may want to mute it.)


  • Online
    Bryan
    4 - Veteran Friend
    Points
    5,784
    Posts
    753
    Quizzes
    4
    Quiz rate
    97.6 %
    • October 12, 2026 at 2:08 PM
    • New
    • #2

    As far as I can tell, in this video, our eyes are seeing a square. A stable square does appear in the movement as the background moves from left to right.

    We are calling it a "square" because the shape we are seeing fits our preconception/basic grasp/mental sense of a square.


    I agree, this does fit the examples Lucretius uses (e.g., a still horse in a river appearing to move when you are on the horse, or a still boat appearing to move when you are in a moving boat), but I think our school listed a lot of examples of "illusions" (i.e., appearances with low symmetry with the original source) before making the argument that, nevertheless, our sensations of appearances are the basis of understanding.


    Our preconceptions/basic mental grasps are just another sensation... they may well be illusionary in some cases (many people have a basic idea of an eternal Jesus), but we must, nevertheless, rely on preconceptions/basic mental grasps for any thought to happen!

    (Technically speaking, an incorrect pro-lepsis/ anticipation is called a hypo-lepsis/ supposition).

  • Online
    Cassius
    5 - Administrator
    Points
    114,827
    Posts
    15,868
    Quizzes
    9
    Quiz rate
    100.0 %
    • October 12, 2026 at 2:44 PM
    • New
    • #3

    Yes, and I almost stayed away from mentioning "illusions" entirely, because i think the basic point is first "what is it that we are seeing" and "how do we decide that we see a "square" and "what is it we are labeling as a square.

    We could use other words (for example, other languages) and mean the same thing. But we're not talking about a "form that we are remembering from before we were born" or a "form of a square that we reason to exist in nature and of which this video demostrates an example"

    We're doing something else, I presume - something like assembling in our minds using a natural faculty a pattern that we choose to call a square, and which when we compare to other things we can see, shares a common set of characteristics. But apparently all this is going on in our minds through nature.

    And I also presume that we would assemble and recognize this pattern even if we were an infant and had never been exposed to any other examples of "things that are square" whatsoever. We aren't born with "the idea of a square" but we are born with a faculty that assembles what we eventually term the idea of a square.

    I think in talking though what the mind is doing we can make clear that what we are seeing is "real" without it partaking in any kind of mystical divine form or hocus-pocus.

    We aren't going to be able to make productive use of understanding "prolepsis" in ethics or anything else if we can't articulate from basic examples what we are talking about.

Finding Things At EpicureanFriends.com

Here is a list of suggested search strategies:

  • Website Overview page - clickable links arrranged by cards.
  • Forum Main Page - list of forums and subforums arranged by topic. Threads are posted according to relevant topics. The "Uncategorized subforum" contains threads which do not fall into any existing topic (also contains older "unfiled" threads which will soon be moved).
  • Search Tool - icon is located on the top right of every page. Note that the search box asks you what section of the forum you'd like to search. If you don't know, select "Everywhere."
  • Search By Key Tags - curated to show frequently-searched topics.
  • Full Tag List - an alphabetical list of all tags.

Resources

  1. Getting Started At EpicureanFriends
  2. Community Standards And Posting Policies
  3. The Major Doctrines of Classical Epicurean Philosophy
  4. Introductory Videos
  5. Wiki
  6. Lucretius Today Podcast
    1. Podcast Episode Guide
  7. Key Epicurean Texts
    1. Chart Of Key Quotes
    2. Outline Of Key Quotes
    3. Side-By-Side Diogenes Laertius X (Bio And All Key Writings of Epicurus)
    4. Side-By-Side Lucretius - On The Nature Of Things
    5. Side-By-Side Torquatus On Ethics
    6. Side-By-Side Velleius on Divinity
    7. Lucretius Topical Outline
    8. Usener Fragment Collection
  8. Frequently Asked Questions
    1. FAQ Discussions
  9. Full List of Forums
    1. Physics Discussions
    2. Canonics Discussions
    3. Ethics Discussions
    4. All Recent Forum Activities
  10. Image Gallery
  11. Featured Articles
  12. Featured Blog Posts
  13. Quiz Section
  14. Activities Calendar
  15. Special Resource Pages
  16. File Database
  17. Site Map
    1. Home

Frequently Used Forums

  • Frequently Asked / Introductory Questions
  • News And Announcements
  • Lucretius Today Podcast
  • Physics (The Nature of the Universe)
  • Canonics (The Tests Of Truth)
  • Ethics (How To Live)
  • Against Determinism
  • Against Skepticism
  • The "Meaning of Life" Question
  • Uncategorized Discussion
  • Comparisons With Other Philosophies
  • Historical Figures
  • Ancient Writers and Texts
  • Decline of The Ancient Epicurean Age
  • Unsolved Questions of Epicurean History
  • Welcome New Participants
  • Events - Activism - Outreach
  • Full Forum List

Latest Posts

  • The Full Epicurean Reasoning Regarding a Material Universe

    Kalosyni October 14, 2026 at 7:17 PM
  • Episode 354 - EATAQ36 - The "Monstrous Absurdity" of Academic Skepticism

    Cassius October 13, 2026 at 9:05 PM
  • Revisiting Issues of The Use of AI in Epicurean Philosophy

    kochiekoch October 13, 2026 at 7:45 PM
  • Welcome MarcyRIzzi

    Cassius October 13, 2026 at 5:38 PM
  • Criticism of Dewitt's interpretation of Principal Doctrine 5.

    Patrikios October 13, 2026 at 2:34 PM
  • Self-Reflection and Decision Making

    Kalosyni October 12, 2026 at 7:06 PM
  • Optical Phenomena (Not Necessarily Just Optical "Illusions") And Their Relationship To Prolepsis / Anticipations

    Cassius October 12, 2026 at 2:44 PM
  • New Advancement on Reading Herculaneum Scrolls

    sanantoniogarden October 11, 2026 at 5:34 PM
  • Thomas More and his "Utopia"

    Martin October 11, 2026 at 7:55 AM
  • Welcome EpicuriousDavid!

    Bryan October 10, 2026 at 4:16 PM

Frequently Used Tags

In addition to posting in the appropriate forums, participants are encouraged to reference the following tags in their posts:

  • #Physics
    • #Atomism
    • #Gods
    • #Images
    • #Infinity
    • #Eternity
    • #Life
    • #Death
  • #Canonics
    • #Knowledge
    • #Scepticism
  • #Ethics

    • #Pleasure
    • #Pain
    • #Engagement
    • #EpicureanLiving
    • #Happiness
    • #Virtue
      • #Wisdom
      • #Temperance
      • #Courage
      • #Justice
      • #Honesty
      • #Faith (Confidence)
      • #Suavity
      • #Consideration
      • #Hope
      • #Gratitude
      • #Friendship



Click Here To Search All Tags

To Suggest Additions To This List Click Here

EpicureanFriends - Classical Epicurean Philosophy

  1. Home
    1. About Us
    2. Classical Epicurean Philosophy
    3. Rules, Terms & Policies
  2. Wiki
    1. Getting Started
  3. Frequently Asked Questions
    1. Site Map
  4. Forum
    1. Latest Threads
    2. Featured Threads
    3. Unread Posts
  5. Texts
    1. Core Texts
    2. Biography of Epicurus
    3. Lucretius
  6. Articles
    1. Latest Articles
  7. Gallery
    1. Featured Images
  8. Calendar
    1. This Month At EpicureanFriends
Powered by WoltLab Suite™ 6.0.27
Style: Inspire by cls-design
Stylename
Inspire
Manufacturer
cls-design
Licence
Commercial styles
Help
Supportforum
Visit cls-design