Genus, Difference, and Lowest Species Reviewed: Why the Division Is Exhaustive, and Are There Lowest Species?

Orientation #

He opens “coming back to where we were yesterday, our last class” and reviews the definitions of genus and difference; later he “goes back to where we left off last time” on the same name being both genus and species (prev. lecture: relative vs. absolute distinctions, lowest species, highest genus). Verified sources place about ten minutes of the class in the handout “The Matter and Order of Wisdom”, p. 4, and in DHB Vol III, p. 453. The previous class treated property and accident and relative distinctions; the next moves to the ten categories.

The class, in order #

1. Review: the five parts of genus and of difference (“everybody knows what genus is now”) #

Point: genus and difference share four parts of their definition and differ only in the fifth.

• Genus: (1) name, the genus of genus; (2) said with one meaning (“univocally”); (3) of many things; (4) other in kind; (5) signifying what it is.
• Because it has one meaning of things other in kind, a genus says only in general what each is, so a further name, difference, is needed to complete the understanding of a kind.
• Difference: first four parts identical; fifth: signifies not what it is but how it is what it is (not merely “how”, which could be accidental).
• Student: of the three types of difference, is the third the principal one, since it is the one defined? Answer: yes, the last definition is what is meant by difference as a name said with one meaning of many things.

2. Two senses of species; the five as an exhaustive division (“only what Porphyry calls the lowest species”) #

Point: “species” has a broad and a strict sense, and only the strict sense figures among the five names.

• Lowest species: name said with one meaning of many things other only individually, signifying what it is.
• Species (broad): name of a particular kind of thing under a genus.
• Relation: every lowest species is a name of a kind under a genus, but not conversely; there is a series of more and less general, and only the bottom member, with nothing other in kind below it, is lowest species.
• The same name can be genus and species only in the broad sense: no genus is a lowest species (said of things other in kind) and no lowest species a genus. The highest genus is a genus and not a species, having no genus above it, as the lowest species has no species below.
• So the five predicables (genus, difference, species, property, accident) are an exhaustive division of names said with one meaning of many things only if “species” means lowest species; any species above that, compared with what is below, is a genus. “You got to stop and think about those things.”

3. How many differences between the three (“only one difference between genus and difference”) #

Point: Porphyry compares genus, species and difference by what they share and where they differ.

• Genus vs. difference: one difference (what it is / how it is what it is).
• Genus vs. lowest species: one difference (other in kind / other only individually); both signify what it is, e.g. “circle” said of many circles.
• Difference vs. lowest species: two differences. So species and difference are further apart in meaning than either is from genus. Both differences in the definition of genus are needed to separate it from both the others.
• A genus or a lowest species can each answer “what is it?”.
• In the Topics Aristotle puts genus and difference together as one dialectical problem, since both signify something pertaining to the nature of the thing, and not convertibly but more generally.

4. Why a definition needs a combination of differences (“Thomas raises a question there”) #

Point: one genus but two or more differences, and no difference alone is convertible with the thing defined.

1. Thomas’s question (commentary on Posterior Analytics): if difference is taken from form, genus from matter, and the unity of the thing requires unity of form, should there not be one difference convertible with the species, as the lowest species is?
2. His answer: because we know natures in an outward way (through the senses), we have no convertible differences; each difference is common to more than one kind, so at least two are needed to specify the thing. Aristotle in Posterior Analytics II, investigating definition by starting from the genus and adding differences, treats differences as non-convertible, though the Metaphysics says genus is to difference as matter to form.
3. This also fits knowing things confusedly before distinctly: each name in the definition, differences included, gives a confused knowledge; only their combination brings the thing “into focus” (a metaphor from the eyes) and makes it distinct.

• Examples: the definition of genus itself: “signifying what it is” alone does not separate genus from lowest species; “of many other in kind” alone does not separate it from difference; together they separate it from both. Square as equilateral right-angled quadrilateral: rhombus is equilateral, oblong right-angled; only square is both.

5. When there is no name: speech instead (“sometimes we don’t have a name for a thing”) #

Point: the five predicables help one see that a speech can play the role of a name.

• Species of quadrilateral have names (square, oblong, rhombus, rhomboid, trapezium; the first four parallelograms); species of triangle do not: “equilateral triangle” is a speech, yet it is a species of triangle as square is of quadrilateral. Do not be tied to having one name.
• Aristotle on the moral virtues between two extremes: temperance lies between excess in sensual pleasure (intemperance, glutton, drunkard, common and named) and the man who enjoys nothing, so rare that there is no name; Aristotle coins one meaning “without sensation”. Probably no point now coining one for equilateral triangle.
• Later we shall meet cases where there is no genus strictly but a word equivocal by reason functions as the first part of the definition.
• Someone defined looking as trying to see; objection that “to see” has many meanings; then looking has three meanings, since to see has three, so is that one definition or not?
• Drama between tragedy and comedy: Renaissance “tragicomedy”; now “romance” (itself many-meaninged; Shakespeare’s last plays are called the romances, not in the romantic sense); the first edition of Shakespeare had no name for it.

6. Order among the differences; the Poetics (“the differences that are in one definition”) #

Point: differences relate to the genus as form to matter, and among themselves there is often an order, the more general first (as in the definition of genus itself); but the order is tricky.

• Aristotle at the start of the Poetics distinguishes the imitative arts by that in which they imitate, what they imitate, how they imitate (acting out vs. narrating: Venus and Adonis and Rape of Lucrece are narrative poems, not plays), with “how” third.
• Why “that in which” before “what”? Argument: Mozart writes both sad and joyful melodies (minor and major), Shakespeare both tragedies and comedies; one art does not unite sad plays and sad melodies. So the unity and distinction of the arts is first by that in which. Mechanical arts likewise: one carpenter makes wooden chairs, tables, houses, bookcases; the metal worker metal chairs and tables (the room’s metal and wooden chairs); to make in metal the carpenter would need different tools and a different way with his matter. An art is an ability to make, first distinguished by its matter.
• But defining tragedy, the thing made, Aristotle gives what it imitates first: a likeness of a course of action that is serious, of some magnitude… then “in sweetened language” (sweetened by meter, metaphor, images). Reason (student): an imitation is a likeness of something, so having said “likeness” one naturally says of what. His own definitions follow the same order: Shakespearean sonnet, a likeness of thought and feeling in fourteen lines of iambic pentameter, three quatrains of alternate rhyme and a rhyming couplet; comedy, a likeness of a laughable course of action.
• Aside: he prefers “likeness” because “imitation” has lost dignity through commercial usage (a cheap likeness).

7. The genus of the predicables and the clue from Summa contra Gentiles (“what is the genus of the predicables”) #

Point: the genus is not just “name” but “name said univocally of many things”, and Thomas confirms the division is exhaustive.

• Summa contra Gentiles I: Thomas eliminates that any name is said univocally of God and creatures, and that every such name is purely equivocal (by chance), reaching the middle position, equivocal by reason. One argument is either-or: every name said univocally of many is genus, difference, species, property or accident; each is eliminated. For the argument to be good the division must be exhaustive, which gave him the clue that the Isagoge is a complete division of name said univocally of many things.

8. Why the division is exhaustive; only three, not four, inside the nature (“why isn’t there a fourth thing”) #

Point: criss-crossing divisions yield genus, lowest species and difference, but no fourth member, for the reason of segment 4.

• Inside the nature vs. outside; within inside: what it is vs. how it is what it is (no third way of pertaining to what it is); of many other in kind vs. many other only individually. What-it-is/other in kind: genus; what-it-is/only individually: lowest species; how/other in kind: difference. The fourth, a difference convertible with the proper species (as “rational” seems with man), is missing, as in the parts of a plot (before-and-not-after, after-and-not-before, both; nothing is neither) three not four (prev.).
• Porphyry’s examples are Platonic (Neoplatonic school): immortal rational animals, aerial spirits like Ariel in The Tempest, so man is mortal rational animal and neither “rational” nor “mortal” is convertible; the example may be false but exemplifies difference as said of many other in kind.
• Heraclitus: “nature loves to hide”, first because nature is within and we know through the senses the outside; we guess the interior from the outside, as we guess about people; hence “think about” and “bring out what the thing is”.
• This fits the third order of knowing (handout: singular in sense before universal understood; outward, almost a synonym for sensible, before inward; confused before distinct): definition is a way from confused to distinct knowledge; if a part were already peculiar to the species you would have arrived before going from confused to distinct.
• Reasoning defined: coming to know or guess a statement through other statements (more distinct than the word); calculating: coming to know or guess a number through other numbers. “Guess”: party of about 25 people at about 4 beers, 100 beers, correct arithmetic on uncertain numbers; likewise reasoning from probable statements is a guess; also a lousy meal last week to “don’t go this week” is certain premises but no necessary following, not a syllogism; one can reason necessarily from merely probable opinions.
• Student: is the genus of that definition “coming to know or guess”? Yes, sometimes just “coming to know”, knowing taken loosely (one knows by experience without reasoning; something hits you on the head). Defining and reasoning share being ways to what you don’t know through what you know: Albert the Great divides logic into the art of the simple unknown (defining) and of the complex unknown (reasoning), anticipated in the Meno (defining virtue, then reasoning whether it can be taught, middle part on how one can investigate what one does not know).
• Property and accident are easier, “odd and even”: follows upon the nature or does not.

9. Relative distinctions and looking before and after (“going back to where we left off”) #

Point: genus and species is a relative, not absolute, distinction, and reason then asks whether there is a first.

• Every science has relative distinctions: double/half; father/son, mother/daughter; cause/effect (not of the same thing); mover/moved: books or erasers lined up, the middle one is moved by this and moves that, a moved mover.
• Reason looks before and after (Shakespeare’s definition, “see how important it is”): cause before effect in the fifth or crowning sense; does every cause have a cause, or is there a first cause? Aristotle treats this universally in the second book of Wisdom, and in natural philosophy and ethics.
• Genus is before species in the third sense, discourse of reason; it resembles the second (being), since animal can be without dog but not dog without animal; students asked “what is a dog?” begin “it’s an animal”.
• Ethics: goods of soul, body, outside; inside better than outside, soul than body; before in the fourth sense.
• Time: every time a time before, or a beginning? Aristotle did not know; in the Topics the eternity of the universe is his example of a probable problem we long to know. Thomas reviews the historical arguments: none conclusive, known by faith (the Big Bang leaves people wondering). Today/yesterday/tomorrow are relative; for our lives there is a first day (grandchildren) and a last; Genesis says time had a beginning, the Apocalypse an end: before in the first sense, time.

10. Are there lowest species and a highest genus? (“is man a lowest species”) #

Point: mathematics shows lowest species clearly; natural science less so; man is proposed as one.

• Square, circle, seven: kinds of quadrilateral but not of square; seven men, dogs, chairs are accidental to seven.
• Dog, cat: not as clear; biologists use reproducing together as a rule of thumb.
• Man: white, black, yellow men are like red, white and blue circles, accidental. Rule: species under a genus require differences determining something intrinsic to the genus: triangle, a plane figure contained by three straight lines, divides into equilateral, isosceles, scalene by all, two, or no sides equal; colour is not a way of being three-sided. If man is an animal with reason, species of man would need kinds of reason; races do not have different reason.
• Heisenberg’s post-war talks: students of all nationalities under Bohr in Copenhagen, the Japanese later making real contributions, against the master race. Heidegger “philosophy speaks Greek”, Schrödinger “science is a Greek way of looking”: Greek contributions, but philosophy is not by definition Greek, though one language may suit it better. Latin lacks the article (medieval Latin inserts “ly”); Greek “deliver us from the evil one” in the seventh petition vs. Latin a malo (the Greek form can be neuter or masculine); some languages lack the verb to be, which “came last”. Quebec joke: send students out to study theology, not in French.
• Student: men and women, some prima facie evidence? He does not go that far. Man may be a lowest species.
• Temperance: moderation in food, drink and sex may be three different kinds; experience might tell. Left there.

His words #

• said with one meaning: his rendering of said univocally.
• what difference: difference signifying how it is what it is.
• lowest species: name said with one meaning of many things other only individually, signifying what it is.
• species (broad): name of a particular kind of thing under a genus.
• highest genus: genus with no genus above it.
• the five predicables: genus, difference, species, property, accident.
• speech: what stands in for a missing name (“equilateral triangle”).
• equivocal by reason / by chance: middle vs. extreme in the Summa contra Gentiles argument.
• likeness: his word for imitation, the genus of the works of the imitative arts.
• sweetened language: language sweetened by meter and metaphor.
• Wisdom: his name for the Metaphysics.
• nature loves to hide: Heraclitus.
• bring out what the thing is: what a definition does.
• reasoning: coming to know or guess a statement through other statements.
• calculating: coming to know or guess a number through other numbers.
• art of the simple unknown / complex unknown: Albert the Great’s division of logic.
• moved mover: what is moved by one thing and moves another.
• crowning sense of before: cause before effect (his fifth sense).
• outward: almost a synonym for sensible.

Texts #

Read in class

• Porphyry, Isagoge: definitions of genus, difference, species; comparison of genus, species, difference.
• Aristotle, Poetics: distinction of imitative arts; definition of tragedy (commented, not read verbatim).
• Handout “The Matter and Order of Wisdom”, p. 4 (verified): the orders of knowing.
• DHB Vol III, The School of Aristotle, p. 453 (verified).

Mentioned

• Aristotle, Topics (genus and difference as one problem; eternity of world as probable problem).
• Aristotle, Posterior Analytics II and Thomas’s commentary (combination of differences).
• Aristotle, Metaphysics (genus/difference as matter/form; book II on first cause).
• Aristotle, Nicomachean Ethics (nameless vices; goods of soul, body, outside).
• Thomas, Summa contra Gentiles I (no name univocal of God and creatures).
• Thomas on the eternity of the world (locus not given).
• Plato, Meno; Albert the Great on the division of logic.
• Shakespeare: The Tempest (Ariel), Venus and Adonis, Rape of Lucrece, the romances; his definition of reason.
• Genesis; Apocalypse; the Lord’s Prayer, seventh petition.
• Heraclitus; Heisenberg; Bohr; Heidegger; Schrödinger.

His questions #

• How many parts are there in the definition of genus, and which separates it from difference? Five; the fifth: what it is vs. how it is what it is.
• How are the two senses of species related? Every lowest species is a kind under a genus, not conversely.
• How many differences between difference and lowest species? Two; one each between genus and the others.
• Shouldn’t there be one difference convertible with the species? No: we know outwardly and confusedly, so a combination of differences is needed.
• Is equilateral triangle a name? No, a speech, but it plays the role of a species name.
• Why does Aristotle distinguish the imitative arts first by that in which they imitate? An art is an ability to make, distinguished first by its matter.
• Why does the definition of tragedy reverse that order? A likeness is a likeness of something.
• In what sense is genus before species? Third sense, discourse of reason.
• Is man a lowest species? Probably: races do not have different kinds of reason.
• Is temperance a lowest species? Left open: perhaps three kinds (food, drink, sex).