11. The Three Divisions: Defining the Soul Through Being and Act

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Lecture Notes

Main Topics #

The Method of Definition Through Division #

• The soul, like time and place, is defined as something of another, requiring division rather than simple enumeration
• Two sets of divisions are necessary: three concerning the soul itself, and three concerning that of which the soul is something (the body)
• This method contrasts with defining a substance like “quadrilateral,” which can be investigated through multiple examples

First Division: The Soul in the Categories (Genera of Being) #

• The soul must be located in the genus of substance rather than quantity, quality, or relation
• Substance is the most fundamental genus of being; all others are accidents dependent on substance
• The word “thing” is used analogically across these genera—substance is most properly a “thing,” while relation is least properly so
• Evidence that the soul is substantial:
  • If the soul were merely an accident (like harmony), it could not exist independently of the body
  • The soul sometimes resists the body’s inclinations, suggesting substantial rather than accidental existence
  • The soul possesses activities that the body cannot account for

Second Division: Matter, Form, and Composite #

• Within substance, three distinctions exist: matter (potency/ability), form (act), and their composite
• Substantial change proves that matter and form exist within the genus of substance
• The soul must be form rather than matter because:
  • The soul is the principle of life and perfection, not potentiality
  • Matter remains after death but in a different form
  • The soul actualizes matter, making it living rather than merely material
• A living body differs from a non-living body as the word “cat” differs from the word “act” (same letters reordered)—the form makes the difference, not the matter

Third Division: First Act Versus Second Act #

• First act (forma): The substantial form or principle of actuality itself (e.g., acquired knowledge of geometry)
• Second act (operatio): The operation or activity flowing from first act (e.g., actively thinking about geometry)
• The soul is a first act rather than second act because:
  • Animals sleep without ceasing to live; life persists without constant operations
  • The soul enables life; it is the principle making vital operations possible
  • First act is prior in being; second act depends on first act for existence

Equivocation and Analogical Predication #

• The word “thing” is equivocally applied across substances, quantities, qualities, and relations
• This equivocation reflects genuinely different modes of being, not merely linguistic confusion
• Substance is most properly a “thing”; accidents are less properly so
• This analogical structure mirrors the structure of causes: the fourfold division of causes corresponds to fourfold meanings of “cause”

Key Arguments #

Why the Soul is Substantial #

1. Independence argument: If the soul can exist apart from the body (as shown for the human soul), it must be substantial, not accidental
2. Resistance argument: The soul resists bodily inclinations; harmony of a body would not resist the body itself
3. Activity argument: The soul performs activities not reducible to bodily properties; only substantial beings have operations independent of accidents

Why the Soul is Form, Not Matter #

1. Principle of perfection: The soul is the cause of life (a perfection); matter is pure potentiality
2. Actualization principle: The soul actualizes matter; it is act itself, not potency
3. Death argument: When death occurs, matter remains but the form changes; the soul (being the form) is what leaves or ceases

Why the Soul is First Act, Not Second Act #

1. Sleep argument: Sleep demonstrates life persists without constant operation; the soul (first act) remains while operations (second act) cease
2. Enabling principle: The soul makes vital operations possible; it is the stable principle, not the transient activity
3. Geometric knowledge analogy: One possesses geometry (first act) even when not actively thinking about it (second act)

Important Definitions #

Key Terms #

• Substantia (Substance): The fundamental genus of being; independent in existence; the locus of all accidents
• Materia (Matter): Pure potentiality; the principle of multiplicity and change within substance
• Forma (Form): Act or actuality; the principle that actualizes matter and gives it its specific nature
• Psyche (Soul): The cause of life; the first act of a natural body possessing life
• Actus primus (First Act): Substantial form; the principle of actuality itself (e.g., knowledge acquired)
• Actus secundus (Second Act): Operation or activity; the exercise of first act (e.g., actual thinking)

Examples & Illustrations #

The Word Analogy (Cat/Act) #

• The letters in “cat” and “act” are identical (same matter) but in different order (different form)
• Just as reordering letters creates difference, so form (not matter) determines whether a body is alive
• The form-order “is not made from the letters, though it exists only in those letters”—similarly, the soul exists only in matter but is not material

The Science of Geometry #

• Before learning: Mind is in pure potency to geometry
• After learning: Mind possesses geometry as first act (knowledge acquired)
• While sleeping: Still possesses the science even without thinking about it
• While actively thinking: Exercising the second act (actual contemplation of geometric truths)
• The soul similarly is first act—enabling life without requiring constant vital operations

Sensing as Immanent Activity #

• Multiple men can share in lifting a table (transitive activity) or pulling a rope (external operation)
• But sensing cannot be divided: if one man sees the crucifix from the front and another from the side, the whole crucifix is not seen together
• Sensing remains within the agent and cannot be shared among multiple subjects (unlike pulling)
• This illustrates the unity of the living being under one soul

Syllogizing and Knowing #

• If one person knows what equilateral means, another knows what right-angled means, and a third knows what quadrilateral means, none can form the definition of a square alone
• One person must see the whole definition: “an equilateral right-angled quadrilateral”
• Like sensing, understanding requires unity within one subject and cannot be distributed among multiple agents

Notable Quotes #

“The soul is the first act of a natural body that has life.”

• Berquist’s formulation of the emerging definition through the three divisions

“The order of the letters is not made out of the letters, even though it exists only in those letters.”

• Clarifies how the soul can be immaterial while existing only in matter; form is real but not itself material

“The word thing here is really different in these cases.”

• Emphasizes that equivocation of “thing” across genera reflects real differences in mode of being

“First act is prior in being; second act depends on first act for existence.”

• Core principle explaining why the soul is first act: it is the stable principle enabling all vital operations

Questions Addressed #

Is the soul in the genus of substance or accident? #

• Answer: Substance (specifically, substantial form)
• Reasoning: If an accident, the soul could not exist apart from the body; but the soul’s independent operations prove it substantial

Is the soul matter or form? #

• Answer: Form, not matter
• Reasoning: The soul is the principle of life (perfection), not potentiality; it actualizes matter rather than being actualized

Is the soul constantly in operation? #

• Answer: No; the soul is first act, not second act
• Reasoning: Animals sleep without dying; plants do not constantly grow; life persists even when vital operations cease

Why can’t multiple subjects share in one soul’s operation? #

• Answer: Because sensing and understanding are immanent activities (they remain within the agent), unlike transitive actions
• Reasoning: This demonstrates the fundamental unity of the living being and proves it is governed by one soul

Methodological Notes #

• Berquist emphasizes that Aristotle seeks brevity (brevitate) in Book 2.12, touching upon divisions rather than developing them fully
• The full development of the first division (categories) belongs to the Categories; the second division derives from Physics Book I; the third division is proper to the investigation of the soul itself
• Understanding these divisions requires background knowledge in logic (categories), natural philosophy (substantial change), and metaphysics (act and potency)