Aquinas (Nature, Psychology, & Ethics) & Occam


Doctrines & Discoveries

Notes & Quotes

Physical Reality, Dual Causality, and Natural Agency


RE: Natural Teleology or Purposiveness:

"Thomas' answer [to the question of the purposes of things] was that the purpose on any thing is what it does "most of the time" -- or, rather, what it does when nothing is interfering with it." (238)

Criticism: "[Thomas'] reasoning here is circular: What things do is what fulfills them, and what fulfills them is what is `natural' to them.  But what is natural to them is what in point of fact they do." (238)

Note: lower functions are for the sake of something higher but also wider, the whole system of nature.

Scientific understanding of natural world is

  • possible since the world is  rationally ordered
  • desirable because knowledge of this order fills us with awe at the wisdom of its divine author.

Scriptural Imperative

"to hold the truth of scripture without wavering"

since "these words of scripture have more authority than the most exalted human intellect" (233)

Dual Causality

God effects his will by the use of created things

as his instruments {3}

and his agents {4}

Natural Agency {2}

each natural kind has its own "proper action" or function

elements: earth, air, fire, water

plants: to growth & reproduction

animals: additionally to move and sense

humans: additionally to think and choose

each kind of individual is fulfilled -- or actualized -- in the performance of its proper function.

each proper function looks beyond itself in a hierarchy of means-ends

elemental stability for the sake of

growth & reproduction for the sake

of movement & sensation for the sake of

of thought & choice

Theology and the Sciences

  • Special sciences are devoted to the limited ends (the personal perfections) that individuals seek.
  • God is the supreme end all things seek.
  • All sciences pass over into -- or are perfected by -- Theology.                                     

1.        He who gives a principle gives whatever results from that principle: thus, the cause that gives gravity to an element gives it downward movement.  (235)

2.        If, therefore, He bestowed His likeness on others in respect of being, in so far as He brought things into being, it follows that He also bestowed on them His likeness in the point of acting, so that creatures too should have their proper actions. (235)

3.        It is also clear that the same effect is ascribed to a natural cause and to God, not as though part were effected by God and part by the natural agent: but the whole effect proceeds from each, yet in different ways: just as the whole of the one same effect is ascribed to the instrument, and again the whole is ascribed to the principle agent. (236)

4.        Further.  It belongs to the dignity of a ruler to have many ministers and various executors of his rule: because the greater the number of his subordinates of various degrees, the more complete and extensive is his dominion shown to be. (236)



Angels: immaterial finite intellects

  • scripture says there are such
  • conceived of as intellects higher than ours but lower than God's
  • not fully actual even though incorporeal
  • only one of each species: wholly distinguished by their forms


The human condition: a little higher than the beasts a little lower than the angels

  • Human beings are the only corporeal substances possessed of thought & free choice
  • Like the angels we can know universal truths and are free to choose for better or worse thereby
  • Like the animals we are endowed with -- and beset by -- sensation & bodily appetites.

Aristotelian Faculty Psychology

  • nutritive faculty: nutrition, growth, & reproduction
  • sensation & desire

five senses ordered according to their natural or spiritual immutation: touch, taste, smell, hearing, sight

higher sensory functions {1}




  • practical reason or intelligence

perfects estimation: compares advantages of various alternatives. {3}

1.        [T]he sheep runs away when it sees a wolf, not because of its color or shape, but a natural enemy.  So too, a bird gathers together straws, not because they are pleasant to the sense, but because they are useful for building its nest.  Animals therefore need to perceive such intentions, which the exterior sense does not perceive.  Now some distinct principle is necessary for this, since the perception of sensible forms comes by an immutation caused by the sensible, which is not the case with the perception of the above intentions. (245)

2.        For the retention and preservation of these forms, the phantasy or imagination is appointed, being as it were a storehouse for the images received through the senses.  Furthermore, for the apprehension of these intentions which are not received through the senses, the estimative power is appointed; and for their preservation, the memorative power, which is the storehouse for such intentions.  (245)

3.        Now we must observe that as to sensible forms there is no difference between man and other animals; for they are similarly immuted by external sensibles.  But there is a difference as to the above intentions: for other animals perceive these intentions only by some sort of natural instinct, while man perceives them also by a certain comparison.  (245)

The Rational Faculty, Active Intellect, and the Freedom of the Will

Averroes' Argument

1.        Only their matter distinguishes individuals, e.g., persons

2.        Active intellect is immaterial.

3.        So, active intellect is not the individual person.


Augustine's Lament:

“The movement of the genital members is sometimes importune and not desired; sometimes when sought it fails, and whereas the heart is warm with desire, the body remains cold.”  (253)

Knowledge and will

  • thought or cognition perfects sensory apprehension
  • will or volition perfects sensory appetition

Cognition or intellect

  • passive:

receives the intelligible forms of things from experience

depends on phantasy & the body

  • active

raises the intelligible forms to actual intellection or conscious conception {1}

is uncompounded and immortal. {2}

is individual contra Averroes: scripture promises our personal survival

Volition or will

  • animals instinctually respond by a "natural instinct" to what is immediately sensed to be advantageous disadvantageous; humans deliberate as to what's advantageous or not in the long run and the big picture (having foresight & circumspection) and choose accordingly (or not).
  • animals react to particulars of their situations; humans act on universal principles of desirability or goodness given their understanding of situations.

Freedom of the Will

  • freedom from coercion: when we are overcome by terror or pain (e.g.) we cannot strictly speaking be said to have willed the outcome since  (i.e., we still do not deem it best all things considered)*
  • contingency: could have done otherwise {3}

if things had been different: no problem.

under these very circumstances: problem*

the will if it so chooses remains in control

to choose contrary to one's every habit and sensory inclination {4,5}

failures will to the seeming contrary

can't control the vegetative functions (Augustine's lament)

can be overcome by (sudden onset of)  sensations, e.g.,  anger.{6}


  • will must be an unmoved mover if we are to be ultimately responsible for our deeds.
  • human acts of will are self-caused
  • while also God-caused -- as with everything else{7}

1.        But since Aristotle did not allow that the forms of natural things exist apart from matter, and since forms existing in matter are not actually intelligible, it follows that the natures or forms of sensible things which we understand are not actually intelligible.  . . .  We must therefore assign on the part of the intellect some power to make things actually intelligible, by the abstraction of the species from material conditions.  And such is the necessity of positing an agent intellect. (246)

2.        {A]ll corruption consists in separation of form from matter.  . . .  Where there is not composition of form and matter, there can be no separation: wherefore . . . there can be no corruption. (248)

3.        The will does not necessarily will whatever it desires. (252)

4.        [Natural] inclinations are subject to the judgment of reason, which the lower appetite obeys. . . .  Therefore, this is in no way prejudicial to free choice. (253)

5.        The adventitious qualities are habits and passions. . . . Yet even these inclinations are subject to the judgment of reason. . . .  It is in our power either to acquire them o, whether by causing them or disposing ourselves to them, or to reject them.  And so there is nothing in this that is repugnant to free choice. (253)

6.        The sensitive appetite has something of its own, by virtue of which it can resist the commands of reason. (253)

7.        Free choice is the cause of its own movement, because by his free choice man moves himself to act.  But it does not of necessity belong to liberty that what is free should be the first cause of itself, as neither for one thing to be the cause of another need it be the first cause.  God, therefore, is the first cause, Who moves causes both natural and voluntary.  And just as by moving natural causes He does not prevent their actions from being natural, so  by moving voluntary causes He does not deprive their actions of being voluntary; but rather He is the cause of this very thing in them, for He operates in each thing according to its own nature. (254)


Everything in its own way seeks both "its own perfection" and "the divine likeness": so, the highest good for us lies in (visionary) knowledge of God. {1}

  • beyond faith {2}
  • beyond description
  • beyond time {3}
  • due to a special "outpouring of the divine goodness" (261)

Virtue & Vice: Natural Law {4}

  • Virtue is self-actualizing activity fulfilling our natures
  • Vice is activity contrary to our natures

1.        Therefore, to know God by an act of intelligence is the last end of every intellectual substance. (259)

2.        The intellect in believing does not grasp the object of its assent. (260)

3.        [T]here is no succession in the vision in question, and . . . whatever is seen in it, is seen at once and in a glance.  Therefore this vision takes place in a kind of participation of eternity. (261)

4.        The evil of drunkenness and of excessive drink consists in a falling away from the order of reason. (267n16)

William of Occam


Theology: Separation of the Spheres of Faith and Reason

  • reason can even contradict faith
  • when it does, faith prevails

Metaphysics & Epistemology

  • Empiricistic skepticism about the external world
  • Nominalism: there are no real universals, only universal signs
  • Occam’s razor
    • “Do not  multiply existence beyond necessity.”
    • aka the principle of “simplicity” or “parsimony” {2}

1.        But … since vision is an absolute thing distinct in place and time from the object …, that vision can remain in existence, the [object] having been destroyed. (318)

2.        But what, in the soul, is this thing which is a sign?  …  For some say that it is nothing but a certain fiction produced by the soul.  Others say that it is a certain quality existing subjectively in the soul, distinct from the act of understanding.  Others say that it is the act of understanding.  And in favor of these there is this to be said: what can be explained on fewer principles is explained needlessly by more.  Everything, however, which is explained through positing something distinct from the act of understanding can be explained without positing such a distinct thing.  For to stand for something and to signify something can belong just as well to the act of understanding as to this fictive entity; therefore one ought not to posit anything else beyond the act of understanding. {322}