89. Powers of the Soul Distinguished by Acts and Objects

Subscribe in Podcast App | Download Transcript

Lecture Notes

Main Topics #

• Translation Problems with ‘Power’ and ‘Ability’: The Greek word dunamis and Latin potentia carry both active and passive senses. English ‘power’ gets stuck on the active meaning (dynamic, potent), while ‘ability’ better captures both active (ability to act) and passive (ability to undergo) meanings. Examples of passive sense: burnable, breakable, beatable.
• The Primacy of Acts over Powers: Although a power may exist before its act in time, the act is prior in definition because a power is essentially ordered toward an act. We know we have an ability only through performing the act for which it is an ability.
• Acts Distinguished by Objects: Acts receive their specific nature from their beginning and end—which are determined by their objects. Heating differs from cooling by having different formal principles and ends.
• Active vs. Passive Powers: Every power is either active (acts upon its object) or passive (is acted upon by its object). These relate to their objects differently.
• The Problem of Contraries: How can the same power know contraries (black and white) if contraries are maximally different? How does the object distinguish powers if the same object can pertain to different powers?

Key Arguments #

The Relationship Between Power, Act, and Object #

• A power, according to its nature as power, is ordered to an act
• The definition of a power must be taken from the act to which it is ordered
• Therefore the definition of the power is diversified as the definition of its act is diversified
• Acts receive their specific nature from their beginning and their end (or limit)
• The object determines the beginning and end of acts
• Therefore powers must be distinguished by their acts, and acts by their objects

Active vs. Passive Powers and Their Objects #

• For passive powers: The object is compared to the act as a beginning and moving cause
  • Example: Color, insofar as it moves sight, is the beginning of vision
  • Example: Being insulted moves one to anger; seeing danger moves one to fear
• For active powers: The object is compared to the act as a limit and end
  • Example: The object of the ability to grow is perfect quantity—the end of growth
  • Example: Heating proceeds from something hot and ends in heat; cooling proceeds from something cold and ends in cold

The Problem of Contraries #

• Objection: Contraries differ most of all; if powers are distinguished by objects, contraries should constitute different powers
• Response: Things that are per accidens (accidental) do not diversify something in species. The difference of color (red, white, blue) is accidental to animal; what diversifies animal is the sensing soul (per se). Similarly, a power regards the common genus (color) rather than specific contraries (black vs. white).
• Example: The same power knows both white and black, just as the same power tastes both sweet and bitter

The Problem of the Same Object Pertaining to Different Powers #

• Objection: If difference of objects gives difference of powers, the same object should give the same power. But the same thing is both known and desired.
• Response: The object is the same in subject but different in its formal ratio (definition)—according to different aspects. Food can be an object of sense (insofar as sensible) and of appetite (insofar as nourishing).

The Problem of Common Sense #

• Objection: Sound and color belong to different sense powers (hearing and sight) but also to one power (the common sense). How does this fit the principle of distinction?
• Response: By the principle that the same objects can pertain to diverse powers according to different formal ratios, and can also belong to a single higher power that receives the operations of the private senses

Important Definitions #

Potentia (Power/Ability) #

• Greek: dunamis
• Latin: potentia
• Definition: That by which something is ordered to an act; what makes a thing capable of acting or being acted upon
• Active power (potentia activa): The ability to act upon something
• Passive power (potentia passiva): The ability to be acted upon; the ability to undergo something

Per Se vs. Per Accidens #

• Per se: Belonging to the nature of a thing as such; essential to it
• Per accidens: Happening to a thing but not belonging to its nature; accidental
• Significance: Things that are per accidens do not diversify a thing in species. Conversely, things that are per se do diversify in species and thus diversify the powers related to them

The Formal Object (Ratio) #

• The aspect under which something is the object of a power
• The same thing can have different formal objects for different powers
• Acts and powers are distinguished ultimately by the formal objects, which determine the beginning and end of acts

Examples & Illustrations #

Examples of Passive Powers #

• Sight: The eye does not act upon colors; colors (insofar as they move sight through light) act upon the eye
• Hearing: The ear does not act upon sound; sound acts upon the ear. Loud sounds can even deafen or overcome the sense of hearing
• Taste: When tasting something very hot or strong, it overcomes the sense of taste temporarily

Examples of Active Powers #

• Digestion: Food is actively broken down by powers within the digestive system
• Growth: The object (perfect quantity for one’s species) is what the growing power tends toward as its end

Heating vs. Cooling #

• Heating: Proceeds from something hot and ends in making something hot (e.g., stove heating water)
• Cooling: Proceeds from something cold and ends in making something cold (e.g., refrigerator cooling wine)
• These differ by their beginning and end, which are determined by their objects

The Problem of Distinguishing Triangles #

• Accidental differences (red, white, blue) do not diversify the species of triangle
• Essential differences (equal vs. unequal sides) do diversify—creating equilateral, isosceles, and scalene triangles
• The same principle applies to powers: accidental differences in objects do not diversify powers; essential differences do

The Example of “Burnable” and Related Terms #

• Burnable: The ability to be burned; destroyed by fire—passive ability
• Breakable, beatable, bustable, corruptible: All express the passive sense of dunamis
• Usage: Even in English, we do speak of something being “burnable” or “breakable,” showing that ability carries the passive sense, even if less naturally than the active

Notable Quotes #

“Power, according as it is power, is ordered to an act… Whence it is necessary that the definition of a power be taken from the act to which it is ordered.” — Thomas Aquinas (on the essential ordering of power to act)

“The definition of the ability must be taken from the act to which it is ordered… And consequently, that the definition of the ability, the understanding of it, be diversified as the definition or the understanding of the act of it is diversified.” — Thomas Aquinas (on how powers are distinguished through acts)

“An object is compared to the act of a passive ability as a beginning and moving cause… But to the act of an active power, the object is compared as a limit and end.” — Thomas Aquinas (on the two ways objects function in relation to powers)

“An act receives its specific nature from its beginning and from its end or turn.” — Thomas Aquinas (on what makes acts distinct)

Questions Addressed #

How do we know we possess an ability? #

Answer: Only through performing the act for which it is an ability. A person blind from birth does not know they lack sight until they encounter others seeing or until an operation might restore it. We know we have the ability to walk by walking, the ability to see by seeing.

If acts come before powers in definition, don’t powers exist first in time? #

Answer: Abilities may exist temporally before their acts (eyes before sight, digestive organs before digestion), but acts are prior in definition and in knowledge because the very nature of an ability is to be for an act. We define what seeing is before we explain what sight is.

How can contraries belong to the same power? #

Answer: A power regards the common genus rather than specific contraries. In the genus of color, black and white are contraries, but the power of sight knows both because it concerns the universal formal object ‘color,’ not specific instances.

How can the same object pertain to different powers? #

Answer: The object is the same in subject but different in its formal ratio or aspect. Food is the object of taste insofar as it is tasteable; the object of hunger insofar as it is nourishing. A single object can thus fall under different formal objects of different powers.

Why do the private senses (sight, hearing, taste, etc.) come together in a common sense? #

Answer: Because we can perceive differences between objects of different senses (e.g., between white and sweet), showing that the private senses have a common center where their objects converge. This is known by inward experience (introspection) and confirmed by outward experience (anatomy of the brain).