ST I q.78 a.3: How the Five Outer Senses Are Distinguished (Natural vs. Spiritual Change)

Orientation #

He opens straight into “Article Three here, Question Seventy-Eight” after the prayer; he recalls “the second book about the soul” on proper and common sensibles and the categories “as we saw” in logic, but says nothing explicit about last class. He closes with Thomas’s “about which distinction one will speak later.” The previous class treated article 2 (powers of the vegetative soul); the next continues the senses, why sight and hearing are more spiritual, and the objections on touch and taste.

The class, in order #

1. Objection 1: nine genera of accidents, so nine senses? (“It seems that the five outward or exterior senses”) #

The article asks whether the five exterior senses are suitably distinguished; the first objection multiplies senses by genera of accidents.

1. Sense is knowledgeable of accidents (contrast: the object of understanding or reason is substance).
2. There are many genera of accidents, as in the study of the categories: quantity, quality, relation, where, when, and so on; even many kinds of quality.
3. Powers are distinguished by their objects. Conclusion: there should be nine senses, or something of the sort, one per genus of accident. He puts the real question underneath: what is special about these accidents (colour, sound…) that makes them the object of the senses and not other accidents?

2. Objection 2 and a review of the categories (“magnitude and figure or shape”) #

The second objection uses the De Anima II division of the sensible to demand extra senses for the common sensibles.

• The De Anima division as he recalls it: sensible as such (per se) vs. sensible not as such but by something else in us knowing when we sense; the per se sensible subdivided into private to one sense (colour, sound, taste) and common to more than one, not necessarily all (shape, magnitude, motion, rest, number).
• Argument: diversity of per se objects diversifies powers; magnitude and figure differ more from colour than sound does; so much more should there be a separate power for magnitude or figure than one for colour and another for sound.
• Digression on the categories, to make the point: the first highest genus is substance (divided material/immaterial, living/unliving, animals/plants, down to us); second, quantity (continuous, geometry; discrete/number, arithmetic); then quality, then relations and so on. Quality has four kinds: (1) habit or disposition, (2) natural ability (ability to understand, to walk), (3) sense qualities, which are what De Anima II called the proper or private sensibles (colour, sound, smell, flavour, the tactile), (4) figure or shape. Thomas gives this fourfold division in the Prima Secundae, where he must show under which species of quality the virtues fall (habit/disposition).
• Student: confused, “what is substance doing up there” among the accidents? He: substance is the first category, the one that stands under all accidents, hence its name; he is just enumerating the categories.
• Student: where did “nine” come from? He: quantity, quality, relation, then the last six (where, when…) make nine genera of accidents; with substance, the ten highest genera.
• The force of the objection restated: colour and sound are subdivisions of one species (sense qualities); figure/shape is a different species of quality, and magnitude is under an entirely different genus (quantity). If colour vs. sound gives sight vs. hearing, objects further apart should give more senses.

3. Objections 3 and 4 on touch and taste; the sed contra (“one sense is of one contrariety”) #

Both remaining objections arise from touch.

• Obj. 3: one sense is of one contrariety (contraries: the forms furthest apart in a genus, white and black in colour, known by sight). Touch knows many contrarieties, hot and cold, wet and dry. So touch is not one sense but many, so more than five senses.
• Obj. 4: a species is not divided against its genus (you do not divide dog against animal). Aristotle often says taste is tactus quidam, a certain kind of touch. So taste should not be laid down as another sense besides touch.
• Sed contra: the Philosopher, De Anima III: there is no other sense besides the five.

4. Three ways of assigning the distinction, and why Thomas rejects them (“Some want to take this from the side of the organs”) #

Thomas lists how people have tried to explain the number of senses and finds none suitable.

• (a) From the organs, according to which element dominates in each (water, air…): as many organs as senses.
• (b) From the medium through which one senses: conjoined (the flesh, in touch) or extrinsic (air or water, in seeing or hearing).
• (c) From the diverse nature of sensible qualities: quality of a simple body vs. of a complex body. In the ancient physics earth, air, fire, water are the simple bodies, distinguished by hot/cold, wet/dry; but the salad dressing or French wine sauce you taste is a complex body. His replies:
• To (a): powers are not for the sake of organs; organs are for the sake of powers. So there are diverse organs because nature institutes them to suit diverse powers, not the reverse. The power is to the organ as act, form to matter (and matter is for the sake of form), or as chief agent to tool (organon means tool). Distinguishing powers by organs is putting the cart before the horse. Example: nature wanted the higher animals to move from place to place for food and shelter, so gave suitable organs, wings to some, fins to others.
• To (b): the diverse media are attributed to diverse senses according as suitable to the acts of those powers.
• To (c): it does not belong to sense to know the nature of sensible qualities, but to the understanding.

5. Thomas’s own principle: what changes the sense as such (“the sense is a certain what? Passive power”) #

The number of senses is taken from what belongs properly and per se to sense.

1. Sense is a passive power, naturally apt to be acted upon by an exterior sensible; Aristotle: sensing is an undergoing. My hearing results from sound acting on my ear, not my ear on sound; seeing from light or colour acting on the eye.
2. Therefore what is perceived by sense as such is the exterior thing insofar as it is able to change the sense (immutativum), and the sensitive powers are distinguished according to the diversity of this. Examples of “as such”: the paper acts on my sight because it is white, not because it is paper; a white face would act on it in the same way, not because it is a face rather than a page. Sugar or salt in the bowl: the eye may not tell which, because it acts on the eye not as sugar or salt but as having a colour, white. “You have to see what it is that moves or changes the sense as such.”

6. Twofold immutation: natural vs. spiritual (“one he calls natural, and the other spiritual”) #

Two ways of being acted upon, on which the whole grading of the senses turns.

• Natural: the form of the changer is received in the changed according to its natural existence, as heat in the thing heated; non-sensing things receive this way (student: the pot on the stove). Others call this material reception.
• Spiritual (not “supernatural”): the form is received according to a kind of spiritual being, as colour in the pupil, which does not thereby become coloured. Others call this immaterial reception.
• The pair as he draws it: matter receives the quality of another as its own quality, losing whatever quality it had (cool water on the burner becomes warm water and loses its coolness); spiritual reception receives the quality of another as the quality of another, while keeping whatever quality one had. “It’s a very subtle thing.”
• Boundary case, touch, the most material sense, where both go on at once: in the shower you feel the warmth most on entering, less after a while, because your skin is by then receiving the warmth as its own quality rather than as the water’s. Reverse case: going into the cold ocean, you must adjust (Rhode Island; in New Hampshire it takes so long it is hardly worth the drive); the coolness is felt more while received as the temperature of something other than my body.
• Michelangelo example: marble chiselled into your shape loses the shape it had and now has your shape as its own; my eye must in some way receive your shape, or I could not recognise you, but it does not become the shape of my eye, nor is some piece of flesh or bone inside me chiselled out; I receive your shape as yours while retaining mine.
• Preview: going down from eye, ear, smell, to taste and touch, there is less spiritual and more material reception.

7. Spiritual reception is required for any sensing (“all natural bodies would sense when they were altered”) #

Sensing in general requires a spiritual change, in which the intention of the sensible form, not its reality, comes to be in the organ, a kind of likeness.

• “Intention”: a reception less than fully real, contrasted with the shape becoming your shape; student confirms it is used only for the immaterial way.
• Otherwise, if natural reception sufficed, every natural body would sense when altered: the water put on for tea each morning would feel the heat of the stove.
• The natural reception is a reception, but not the one that is sensing: the marble does not know your shape; the water does not feel the stove. His cat as a boy, smelling something good, jumped on the stove, singed her paws and never tried again: she received the heat differently from the meat on the stove, as the quality of something other than herself.

8. Grading the senses by the natural change involved (“In some senses, there is found a spiritual immutation”) #

Thomas’s next paragraph sorts the senses: sight spiritual only; hearing and smell add a natural change on the side of the object; touch and taste on the side of the organ.

• Sight: immutatio spiritualis tantum. Caveat: Aristotle or Thomas may have thought sight more spiritual than it is; we know about photons hitting the optic nerves. Still sight seems more spiritual than the others; a sign is our transferring “seeing” to understanding, which is altogether immaterial. The order stays the same even if we do not go all the way with Thomas.
• Hearing: natural change on the object’s side according to place, since sound is caused by percussion and commotion of the air (today we would put it more sophisticatedly).
• Smell: natural change on the object’s side according to alteration; the body must be altered in some way through heat to give off an odour. Student: so it is really the heat, and the more intense the heat, the more odour; he: somewhat exaggerated, but there is some alteration, even food corrupting in the refrigerator is a kind of cooking or alteration. Sound is less intrinsic, a locomotion, and travels faster; in smell the alteration process itself emits the odour.
• Touch and taste: natural change on the side of the organ. The hand touching the hot thing itself becomes hot; the tongue is moistened through the moistness of the flavours. Dry mouth from breathing through a clogged nose; licking a lifesaver moistens the tongue as the candy becomes liquid. Student: we would understand the moisture as activating our own rather than coming from the flavour; he: it may be more complicated than Thomas sees.
• Organs of smell and hearing undergo no natural change in sensing except per accidens.
• Result: sight most spiritual, then hearing and smell, least touch and taste; touch and taste are also more limited, working by immediate contact, taste being almost within you. Thomas’s commentary on the Psalms, “taste and see how sweet is the Lord”: “taste” is used because taste is interior; one experiences within himself something pleasant.
• Asides: pancakes and sausages smelled all through 7:30 Mass, the kids downstairs raising money for a trip to Boston; a student jokes the pastor should have scheduled it for the homily on transubstantiation. His package-store colleague’s Labor Day breakfast on the outdoor grill at six, waking the neighbourhood by the smell. The shared refrigerator on Cedar Street in his bachelor days: someone’s thing pushed to the back corrupts and makes its presence known to everyone; the same in a stocked family fridge.

9. Sight most perfect and most common; hearing before smell (“sight, which is without a natural undergoing”) #

Thomas’s concluding ranking, with the reasons.

• Sight, without natural change of organ or object, is most spiritual (with his caveat), most perfect among the senses, certainly in clarity: when something is clear to another sense we say “see” (“taste this… oh, I see what you mean”; in music appreciation, “now listen to Badura-Skoda playing that… oh, now I see”), and we carry the word up to higher things, even the beatific vision, seeing God face to face.
• Communior: its object is more common, we know things at a distance, the sun, moon and stars depend on sight; we do not hear as far as we see. Hearing reaches further than smell: hammering ricochets to the neighbour’s house, the kitchen smell does not.
• After sight, hearing, then olfactus, both with natural change on the object’s side; hearing first because its change is local motion, which is more perfect than and naturally prior to alteration, as proved in Physics VIII. Reason given: what is moved in place is already complete, whereas what is altered is being changed inwardly, on the way to being perfected.
• Touch and taste sunt maxime materiales; “about which distinction one will speak later” (where he stops).

His words #

• theorem: “the old word,” something to look at (opening fragment, before the prayer)
• outward or exterior senses: the five senses of the article
• private sensibles / proper sensibles: known by one sense only [ed.: proper sensibles]; common sensibles: known by more than one, not necessarily all
• natural ability: second species of quality, e.g. ability to understand or walk [ed.: natural potency]
• sense qualities: third species of quality, identical with the proper sensibles
• tactus quidam: Aristotle’s “a certain kind of touch,” said of taste
• organ / organon: “means tool”; organs are for the sake of powers
• passive power: apt to be acted upon by its object; sensing is an undergoing
• immutativum / “exterior immutativum”: what from outside is able to change the sense, as such
• natural immutation = material reception: receive another’s quality as one’s own, losing one’s own
• spiritual immutation = immaterial reception: receive another’s quality as another’s, keeping one’s own; not “supernatural”
• intention (of the sensible form): the likeness received, “less than fully real,” used only of the immaterial way
• immutatio spiritualis tantum: Thomas on sight; he prefers “more of this than the other ones”
• olfactus: smell
• communior: its object is more common, known at a distance
• maxime materiales: touch and taste

Texts #

Read in class

• Thomas, Summa theologiae I, q. 78, a. 3: four objections, sed contra, and the corpus down to “about which distinction one will speak later” (replies not reached)
• Aristotle, De Anima II (the division of sensible per se into proper and common), recalled
• Aristotle, De Anima III: no other sense besides the five (in the sed contra)

Mentioned

• Aristotle, Categories (“study of the categories”; the ten highest genera, four species of quality)
• Thomas, Summa theologiae, Prima Secundae: the fourfold division of quality, applied to the virtues (no question stated)
• Aristotle, Physics VIII: local motion prior to alteration
• Thomas, Commentary on the Psalms: “taste and see how sweet is the Lord”

His questions #

• What is special about these accidents that makes them the object of the senses and not other accidents? Answered in the corpus: what is able to change the sense from outside, as such, is its per se object.
• Why don’t you have a different sense for figure or shape, and a different one for quantity? Left open in this class (objection 2 stated; the reply is not reached).
• Is the power for the sake of the organ, or the organ for the sake of the power? The organ for the power, as matter for form and tool for agent; so organs cannot be the reason for the number of senses.
• Does the sugar or salt act upon the eye because it is sugar or salt? No, because it has a colour, white; that is what moves the sense as such.
• If only natural reception sufficed for sensing, what would follow? All natural bodies would sense when altered; the kettle would feel the stove.
• Why do you feel the warmth of the shower more when you first get in? Because later your skin receives the warmth as its own quality, not as the water’s.
• Why is hearing ranked before smell? Its natural change is local motion, prior to and more perfect than alteration (Physics VIII), and it reaches further.
• Why does the Psalm say “taste and see”? Because taste is interior, something experienced within oneself as pleasant.