Plato: Psychology, Sociology, & Theology



Quotes & Notes

Psychology & Sociology


Three parts of the Soul:

1.        the rational

2.        the prideful

3.        the pleasure seeking


Segue from ethics

kinds of pleasure

mixed (up with pain): bodily {1}

pure unmixed: mental

Virtue or Justice (of selves or states) = good functioning: virtue is mental health.

Organisms & their organs

Individuals as organisms: functional systems

 various organs (stomach, eyes)

 have various functions (digesting, seeing) -- purposes they perform for the sake organism's purpose (living).

and virtues (e.g. acuity of vision)

The polis or community is an organism: a functional system

Individuals & subgroups are the organs (or instruments)

With virtues according to their societal role

Workers: Temperance or Moderation

Guardians: Courage

Rulers: Knowledge or Wisdom

Individual Virtue = balance &  harmony among 3 divisions of the Self

moderate pursuit of pleasure, tempered by

the courage or strength of character to do the right thing

that reason determines

1.        "Do you see the inference -- that pleasure and pain are simultaneous, when you say that being thirsty, you drink?"

2.        “The just man does not allow the several elements in his soul to usurp one another's functions; he is indeed one who sets his house in order, by self-mastery and discipline coming to be at peace with himself, and bringing into tune those three parts."

3.        “Then in the larger the quantity of justice is likely to be larger and more easily discernible. I propose therefore that we enquire into the nature of justice and injustice, first as they appear in the State, and secondly in the individual, proceeding from the greater to the lesser and comparing them.”

4.      “[T]he individual soul, like the State, has been divided by us into three principles ….”

5.        “[W]e must have knowledge of equivalence and nonequivalence before we use our senses, or we would not be able to make any sense of them.”

Natural Theology


“Philosophy begins in wonder.”

Informed by reason, not any claimed supernatural revelation. 

From God's perfect goodness reason can infer:

God is not the author of hurtful things (since nothing good is hurtful); so God is not the author of all things; God doesn't practice deception. {1}

God is the author of all benefits and, in particular, since punishment received for wickedness (since such punishment is beneficial).

God is unchangeable: change from perfection could only be for the worse.

1.      “[G]od is not the author of all things … of the evils the cause is to be found elsewhere.”

2.      “[T]he creator, reflecting … that no unintelligent creature … was fairer than the intelligent … and that intelligence could not be present in anything which was devoid of soul. For which reason, when he was framing the universe, he put intelligence in soul, and soul in body, that he might be the creator of a work which was by nature fairest and best.

Movement, Self-Movers, and God

observable types of motion

circular motion around a fixed center


combination & separation

increase & decrease

becoming & perishing

metaphysical distinction among types of movers or motions

not self-moving


Argument for a self-moving mover or movers

there must be a first cause of movement

only a self-mover could be such a first cause

"soul" is the name given to self-movers

Circular motion is most akin to the "motion of reason"

 its regularity & simplicity commends it

the planets and stars are gods (they must be moved by very good, very rational souls).

The Cosmos is the Living Creature (intelligent and spontaneously moving).  The supreme God (the Good) is World Soul.   So the Cosmos is goal directed, and well-ordered to achieve its end or goal, the Good

1.        "[We must distinguish] that motion which is always able to move other things, but unable to move itself; and that motion which always is able to move both itself and other things."

2.        "[I]nasmuch as it has been shown that [the heavenly motions] are all caused by one or more souls, which are good also, with all goodness, we shall declare these souls to be gods."

3.        "[A]ll things are ordered systematically by Him who cares for the World-all with a view to the preservation and excellence of the Whole, whereof each part, so far as it can, does and suffers what is proper to it."

4.      "[T]he world is like, above all things, to that Living Creature of which all other living creatures, severally, and in their families, are parts."