38. Eternity, Time, and the Aevum: Their Distinctions and Measures

Subscribe in Podcast App | Download Transcript

Lecture Notes

Main Topics #

The Three Measures of Duration #

• Eternity: The measure of permanent, unchangeable being; proper to God alone
• Time: The measure of motion and change; the number of motion according to before and after
• Aevum: An intermediate duration proper to spiritual substances (angels) and celestial bodies; all-at-once in being but with before and after in operations

The Essential Difference Between Eternity and Time #

• The crucial distinction is NOT whether duration has a beginning and end
• Rather, the essential difference lies in totesimo (all-at-once character)
• Eternity is totesimo: all at once, without before and after
• Time necessarily has before and after—this is its defining characteristic
• This difference would persist even if time were infinite in duration
• Boethius: “The now that flows makes time; the now that stands still makes eternity”

Time and Its Characteristics #

• Time is defined as “the number of motion according to before and after”
• The now (nunc) of time is constantly moving forward; it “waits for no man”
• The now of time differs in position throughout motion, similar to a body moving through space
• Time measures things with beginning and end, but also things merely capable of motion and rest
• Even the eternal heavenly bodies, though unchanging in substance, are measured by time in their local motion (though only their individual circulations have measurable duration)

Boethius’s Definition of Eternity #

• “The all-at-once and perfect possession of unending life” (totesimo et perfecta possessio vitae interminabilis)
• Each element is essential:
  • Totesimo (all-at-once): negates before and after
  • Perfect: negates imperfection and incompleteness
  • Possession: emphasizes active holding, not mere absence
  • Unending: negates beginning and end
  • Life: includes operation, not mere being

The Aevum as Intermediate Duration #

• Has being that is unchangeable (all-at-once, like eternity)
• But has operations with before and after (like time)
• Examples: an angel’s substantial being is unchangeable, but its thoughts and choices involve succession
• Creatures measured by aevum do not undergo substantial change, but they do experience change in their operations and acts
• One aevum only for all aevernal things, measured by the first aevernal being (just as one time measures all temporal things through the first motion)

Why These Distinctions Cannot Be Based Solely on Beginning/End #

• If the distinction rested only on whether duration has beginning and end, then:
  • Infinite time would be identical to eternity
  • The distinction would be accidental, not essential
• Thomas’s response: Even if the heavenly bodies moved eternally, time would still differ from eternity
• The distinction is necessary: it follows from the very nature of what is being measured (permanent being vs. motion vs. aevernal being)

Key Arguments #

Against the Position That Time and Eternity Differ Only by Beginning/End #

• Objection: If time always was and always will be, there would be no difference from eternity
• Response: The essential difference is totesimo (all-at-once), not duration’s endpoints. Eternity is all-at-once; time necessarily has before and after. This remains true even with infinite time.
• Further clarification: Even if eternal things always existed and always will exist, they would still differ from God’s eternity by possessing before and after in their operations

On Why Only Part of Infinite Duration Can Be Measured #

• If time were infinite and always existed, it could not be measured as a whole (the infinite cannot be measured)
• But individual portions—a day, a year, a circulation of the heavens—would still be measurable
• The infinite cannot be the object of numbering or measurement as a totality
• This shows why time requires limits (beginning and end) to be fully actual as a measure

The Unity of Time and Aevum #

• Principle: The simplest thing in a category is the measure of all others in that category
• Application to time: All motions ultimately depend on the first motion of the heavens; thus one time measures all temporal things
• Application to aevum: All aevernal beings depend on the first aevernal being (God); thus one aevum measures all aevernal things
• Against multiplicity of aevum: Different angels do not cause one another; yet they share one aevum because they are all measured by the first aevernal being

On the Relationship Between Changeability and Time/Eternity #

• Things measured by time have changeable being: either being consisting in motion (corruptible things) or being subject to motion (celestial bodies in local motion)
• Things measured by aevum have unchangeable being but changeable operations joined to it
• Things measured by eternity are altogether unchangeable in both being and operations
• This grounding in changeability explains why time measures not only things actually moving but things capable of moving

Important Definitions #

Eternity (Aeternitas) #

• The all-at-once and perfect possession of unending life
• Characterized by: complete absence of before and after, immutability, permanence of being, indivisibility
• Proper to God alone; creatures participate in it only through grace or in operations (beatific vision)

Time (Tempus) #

• The number of motion according to before and after (numerus motus secundum prius et posterius)
• Requires succession and a numbering subject (soul)
• Measures both things actually changing and things capable of change
• Composed of fleeting moments (nows) always different in position

The Now (Nunc) #

• In time: indivisible point between past and future, always moving forward (flowing now)
• In eternity: standing still, immobile, containing all moments simultaneously (standing now)
• The now of time differs in definition (position) throughout the flux of time
• The now of eternity remains the same in both subject and position

The Aevum (Aevum) #

• Duration proper to spiritual substances (primarily angels) and celestial bodies in Aristotelian cosmology
• All-at-once (totesimo) in being, but having before and after in operations
• Unchangeable in substance; capable of succession in acts, thoughts, and choices
• Neither consists in change (unlike time) nor free from all changeability (unlike eternity)

Permanent Being (Esse Permanens) #

• Being that does not consist in motion or change
• The foundation of eternity as its measure
• Contrasts with being in motion (esse in motu), the foundation of time

Examples & Illustrations #

The Moving Body (Illustration of the Now of Time) #

• The now of time is like a body throughout a motion: the same body in subject, but different in position
• Just as a body’s position changes while remaining the same body, the now remains the same instant but is constantly in a new “position” relative to past and future
• This illustrates why time is infinitely divisible: just as motion has infinite positions

The Garments of Lady Wisdom (From Commentary on Consolation) #

• In medieval commentaries on Boethius, Lady Wisdom is depicted with the Greek letter π (pi, practical philosophy) at the bottom and θ (theta, theoretical philosophy) above it
• The symbolism shows theoretical above practical, as Christ says “Mary has chosen the better part”
• Her garments are torn, symbolizing how men, in grasping at truth, rip it apart: one man gets one piece, another gets another piece
• This illustrates the fragmentation of human knowledge contrasted with divine eternity

Infinite Being and Non-Measurability #

• Shakespeare’s image: “common mother, thou whose womb immeasurable and infinite breast teems and feeds all”
• The infinite cannot be measured as a whole; yet parts of the infinite can be measured (one year, though time itself is infinite)
• Applied to the aevum: though aevernal duration is infinite on the side of the future, the being of angels remains measurable in parts through their individual operations

The Unchangeability of Celestial Bodies #

• Celestial bodies have unchangeable substantial being (substantial immortality)
• Yet they have changeability in local motion (from one place to another)
• Thus they are measured by the aevum in their substance but (in Thomas’s view) pass through time in their motion—or more precisely, are measurable by time only in their circumulations (individual orbits), not in their whole duration

Augustine’s Statement on Spiritual Creatures and Time #

• Augustine says God moves spiritual creatures “through time” (in Genesis commentary, ad litteram)
• This is properly understood as meaning: in their affections and understandings (operations with succession), angels are measured by time
• But in their natural being, they are measured by the aevum
• In their vision of God’s glory, they partake of eternity

Notable Quotes #

“The now that flows along makes time. The now that stands still makes eternity.” — Boethius, Consolation of Philosophy

“Even if time always was and always will be, there would still remain a difference between eternity and time, as Boethius says, from the fact that eternity is totesimo, all at once, which does not belong to time.” — Thomas Aquinas, cited in lecture

“Time waits for no man.” — Common saying, illustrating the fleeting, always-forward-moving character of time’s now

“Eternity is the measure of a permanent being, time is the measure of motion. The being of corruptible things, because it is changeable, is not measured by eternity, but by time.” — Thomas Aquinas, cited in lecture

Questions Addressed #

How Can Eternity Differ from Time If Time Could Be Infinite? #

• Resolution: The difference is not in having or lacking beginning/end, but in the all-at-once character (totesimo). Eternity is all-at-once without before and after; time essentially consists in before and after. This distinction is necessary and would hold even if time were infinite.

Why Is Time the Number of Motion? #

• Resolution: Motion has continuous passage from one state to another. Numbering divides this continuous flux into countable units (before and after). Time is this numbering in the soul, counting the division of motion according to before and after.

Does Infinite Duration Make Something Immeasurable? #

• Resolution: Yes, if considered as a whole. But parts of infinite duration can be measured. The infinite as a totality escapes measurement because measurement requires limits. Thus, if time or aevum extended infinitely, they would not be wholly measurable, but their circulations or individual spans would be.

What Is the Aevum and How Does It Differ from Both Eternity and Time? #

• Resolution: The aevum is an intermediate duration. Like eternity, it has no innovation or aging in the being of the thing measured (angels’ substantial being is unchanged). Like time, it admits of before and after, specifically in operations and successive acts. It is measured neither by eternity nor by time, but by itself—specifically, by the first aevernal being.

Is There One Aevum or Many? #

• Resolution: One aevum only, because all aevernal things depend on the first aevernal being (God). Just as one time measures all temporal motions through dependence on the first motion, one aevum measures all aevernal beings. The principle is that the simplest thing in a category is the measure of all others in that category.

How Can Angels Have “Before and After” While Having Unchangeable Being? #

• Resolution: The before and after in the aevum concerns their operations (thoughts, choices, acts of understanding), not their substantial being. An angel’s being is all-at-once (like eternity), but the angel’s thinking is one thought followed by another (like time). The being is unchangeable; the operations are successive.

Structural and Pedagogical Notes #

On the Method of Distinguishing Things #

• Berquist emphasizes Thomas’s method of defending axioms common to all men (being, one, whole, part, etc.)
• Understanding words and concepts common to all is prerequisite to understanding particular sciences
• The teacher must lead the student from what is already known to what is new; this requires common ground
• Thomas, as the “Common Doctor,” understands these universal concepts better than others

On Division and Subdivision #

• Thomas typically divides topics into two or three parts, then subdivides
• Complex divisions (four or more) usually result from crossing two simpler divisions
• Example: Students classified as (1) want to know/don’t want, × (2) able to know/unable → four groups
• In divine things (faith, hope, charity) and scripture (law and grace, or Old Testament law and Father, New Testament three parts), the division into two or three reflects the natural order of the subject matter

On Analogy and Participation #

• Understanding spiritual and eternal things requires beginning with bodily and temporal things
• Words originally referring to space extend metaphorically to non-spatial realities
• Etymology shows this: differentia (to carry apart), intelligo (to stand under), supereminens (above)
• This principle undergirds all metaphysical language about God: we know God’s transcendence through negation of creatures