Logic (2016) #

A comprehensive treatment of classical Aristotelian logic. These lectures cover the three acts of reason, the ten categories, syllogistic reasoning, and dialectical tools as presented by Aristotle and St. Thomas Aquinas, providing the foundational art for all philosophical and theological inquiry.

53 episodes, about 51 hours

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Classes #

Class 1 · The Equivocity of “Logos”: From John’s Gospel to Thomas’s Division of Logic #

2016-10-06 · 42 min Berquist traces the Greek word “logos” from John’s Gospel through Aquinas’s prologues to the logical commentaries, showing how one equivocal term shapes his division of logic.

Class 2 2016-10-13 #

Part 1 of 2 · Logic’s Three Acts of Reason, Univocal and Equivocal Names, and the Genus #

69 min Berquist opens the study of logic with Aquinas’s three acts of reason, then turns to Porphyry’s Isagoge to work out univocal versus equivocal names and the predicable “genus.”

Part 2 of 2 · Porphyry’s Five Predicables: Difference, Species, Property and Accident #

58 min Berquist works through Porphyry’s Isagoge on genus, species, and difference, then turns to property and accident, using triangles and squares to show how each predicable functions in a definition.

Class 3 2016-10-20 #

Part 1 of 2 · Ante-Predicaments I: Highest Genera, Being as a Name for Everything, and Equivocal, Univocal and Derived Names #

64 min Berquist opens Aristotle’s Categories, working through equivocal, univocal, and denominative naming to show why “being” cannot be one single genus but must divide into several highest genera.

Part 2 of 2 · Ante-Predicaments II: Said Of and In a Subject, Individual Substance, and the Ten Categories #

70 min Berquist works through Aristotle’s Categories, chapter one’s division of things “said of” and “in” a subject, and chapter three’s rules for predication across genus and species.

Class 4 2016-11-03 #

Part 1 of 2 · The Ten Categories in Aristotle’s Text and Thomas on Being Divided by Ways of Predication #

68 min Berquist works through chapter four of Aristotle’s Categories — the ten highest genera, from substance to passion — then turns to Aquinas on why being divides non-univocally into these predicaments.

Part 2 of 2 · Deriving the Ten Categories: Substance, Inherent Accidents, and Extrinsic Denomination by Cause and Measure #

60 min Berquist works through Aquinas’s commentary on chapter four of Aristotle’s Categories, deriving all ten predicaments from three ways a thing gets named: by its own substance, by an inherent accident, or by extrinsic denomination from cause or measure.

Class 5 2016-11-10 #

Part 1 of 2 · Being Divided into the Ten Categories: Thomas’s Exposition of Metaphysics V (and Why Being Is Not a Genus) #

60 min Berquist works through Thomas’s exposition of Metaphysics V to show why “being” cannot be a genus, dividing instead into the ten categories—substance, quantity, quality, relation, and the rest.

Part 2 of 2 · Crossing Two Divisions, How Words Become Equivocal by Reason, and the Start of the Chapter on Substance #

65 min Berquist crosses two two-part divisions to derive real distinctions, then works through how words become “equivocal by reason” in Aristotle’s Categories, ch. 5, before starting the chapter on substance.

Class 6 2016-11-17 #

Part 1 of 2 · First and Second Substance, and How Words Take On Related Meanings (Analogy vs. Equivocation by Reason) #

65 min Berquist works through Aristotle’s Categories on first and second substance, then asks how words like “healthy” or “disposition” carry related but not identical meanings across different uses.

Part 2 of 2 · The Properties of Substance, the Hypostasis of Christ, and Thomas’s Texts on Substance #

53 min Berquist works through Aristotle’s properties of substance in Categories chapter 5, then digresses into Aquinas on divine naming and how “substance,” “hypostasis,” and “person” apply to Christ.

Class 7 2016-12-01 #

Part 1 of 2 · The Beauty of Order: Numbers in the Treatise on the Trinity, Limit in Art, and Why the Genera of Being Are Not the First Distinction #

64 min Berquist moves from the numerical order of the Trinity to Aristotle’s Categories, working through the division of the genera of being and the discrete versus continuous species of quantity in chapter six.

Part 2 of 2 · Quantity by Its Parts and Measures: Two Definitions of the Continuous, Logician versus Wise Man, and Music versus Painting #

60 min Berquist works through Aristotle’s Categories, chapter six, on quantity, pressing why lines divide differently than numbers and why music outranks painting among the arts.

Class 8 2017-01-05 #

Part 1 of 2 · Divisions of Five, the One Convertible with Being, and the Species of Quantity #

66 min Berquist works through Aristotle’s Categories, chapter 6, on the species of quantity—discrete versus continuous—while tracing how fivefold divisions recur across logic, nature, and theology.

Part 2 of 2 · Quantity, Time and Reason: Individuation, the Properties of Quantity, and Number as Abstraction #

58 min Berquist works through Aristotle’s Categories, chapter 6 on quantity, tracing how line, surface, body, place, time, and number divide by boundary and position—and why time alone has order without position.

Class 9 2017-01-12 #

Part 1 of 2 · Categories, Chapter 6 on Quantity: Intentions of the Mind, Number and the Unity of Piles #

46 min Berquist works through Aristotle’s Categories, chapter 6, on quantity, using it as a springboard into Aquinas on genus, number, and why a pile of stones isn’t one thing the way a man is.

Part 2 of 2 · From Quantity to ‘Towards Something’: Categories, Chapter 7 on Relation #

50 min Berquist finishes Aristotle’s Categories chapter six on quantity, then opens chapter seven on relation, asking why relatives are treated before quality despite the reverse order of enumeration.

Class 10 2017-01-19 #

Part 1 of 2 · Predication and the Category of ‘Towards Something’: Cajetan, Aristotle’s Two Definitions, and the Senses of Being #

44 min Berquist works through Cajetan’s commentary on Aristotle’s category of “toward something” (ad aliquid), distinguishing Plato’s looser definition from Aristotle’s stricter one, then applies the distinction to Aquinas on relations in the Trinity.

Part 2 of 2 · Real Relations and Relations of Reason: Knowledge, God’s Unchanging Eternity, the Trinity, and Why God Allows Evil #

41 min Berquist works through Aquinas’s De Potentia distinction between relations secundum esse and secundum dici, real relations and relations of reason, then applies it to the Trinity and to why God permits evil.

Class 11 2017-01-26 #

Part 1 of 2 · Relation, Part 1: Relatives Secundum Esse and Secundum Dici, the Trinity, and Beings of Reason #

45 min Berquist opens Aristotle’s Categories, chapter 7, on relation, distinguishing things whose whole nature is toward another—like double and half—from things merely implying a relation, like knowledge or power.

Part 2 of 2 · Relation, Part 2: Thomas on Real Relations and Relations of Reason, and the Weak Being of Relation #

60 min Berquist continues on the category of relation, distinguishing relatives said “secundum esse” from those “secundum dici” and asking when a relation is real rather than merely conceptual—including the odd case of divine relations like Father and Son.

Class 12 2017-02-02 #

Part 1 of 2 · Relation (Ad Aliquid): Real Relations, Their Causes, and the Knower and the Known #

50 min Berquist works through Aquinas on relation (ad aliquid) as a category of being, asking what makes relations like paternity and equality real rather than merely mental.

Part 2 of 2 · Relations of Reason in De Potentia, and Aristotle’s Chapter on Quality #

68 min Berquist works through Aquinas’s De Potentia on relations of reason—how God can truly be called “Lord” and “Creator” without a real relation to creatures—then turns to Aristotle’s Categories, chapter 8, on quality.

Class 13 2017-02-10 #

Part 1 of 2 · Relations of Reason and the Four Species of Quality: Dividing by Two or Three, Virtue as the Road to Happiness, and Number in the Trinity #

61 min Berquist works through Aristotle’s four species of quality in Categories ch. 8, testing whether they divide by two, three, or four, and traces how Aquinas draws on the scheme to treat virtue.

Part 2 of 2 · Quality Said in Many Ways: Qualis and ‘How’, Why Habit Comes First (Prima Secundae), Modus, and the Four Senses of End #

62 min Berquist works through Aristotle’s Categories, ch. 8 on quality—figure, capacity, passion, habit—and asks why habit comes first in Aquinas’s treatment, before turning to the four senses of “end.”

Class 14 2017-02-16 #

Part 1 of 2 · Quality in Theology: Powers, Grace, Sacramental Character and Words Taken from the Continuous #

62 min Berquist works through Aquinas’s commentary on chapter 8 of Aristotle’s Categories, tracing the four species of quality and then asking how grace and sacramental character fit—or don’t—into that scheme.

Part 2 of 2 · The Last Six Categories, God’s Eternity, and a Review of the Ante- and Post-Predicaments #

56 min Berquist works through the last six of Aristotle’s ten categories—where, when, position, having, action, passion—and reviews how the Categories divides into Ante-, Post-, and the Predicaments proper.

Class 15 2017-02-23 #

Part 1 of 2 · The Post-Predicaments I: Opposites, Distinction, and Speaking of Nothing #

61 min Berquist works through Aristotle’s post-predicaments in the Categories—the four kinds of opposition, priority, and simultaneity—using Aquinas’s commentary to show how these distinctions run through all philosophy.

Part 2 of 2 · The Post-Predicaments II: Before, Together, Motion, and Having (God’s Goodness and Seeing Him Face to Face) #

63 min Berquist works through Aristotle’s Categories on “prior,” “simultaneous,” motion, and “having,” showing how Aquinas applies these terms to speech about the Trinity and the divine attributes.

Class 16 2017-03-02 #

Part 1 of 2 · Kinds of Opposites and the Trinity: Heaven’s Praise, Evil as Privation, and Why the Father Is Not Before the Son #

69 min Berquist works through Aristotle’s four kinds of opposition—contradiction, privation, contraries, relatives—then applies them to evil as privation and to why the Father is not prior to the Son.

Part 2 of 2 · Relations of Reason, Eternity as ‘Whole at Once’, Motion Among the Post-Predicaments, and an Introduction to the Second Act of Reason #

61 min Berquist asks whether God’s priority to the world is a real relation or only one of reason, then works through Boethius’s definition of eternity as the “whole and perfect possession of unending life at once.”

Class 17 2017-03-09 #

Part 1 of 3 · Senses of Before and After, and the Eight Senses of ‘In’ as Ways of Thinking Out #

62 min Berquist works through the senses of “before and after,” including a causal sense, and then maps the eight senses of “in” from Physics Book IV onto eight corresponding ways of thinking things out.

Part 2 of 3 · The Order of Thinking Out: Definition, Understanding What a Thing Is, Name and Speech #

46 min Berquist traces the order of mental operations—from division through definition to statement and conclusion—drawing on Aristotle’s Categories, Porphyry’s Isagoge, and Aquinas’s proemium to logic.

Part 3 of 3 · Truth and Falsity in Statements: Either/Or and If-Then Statements and Syllogisms #

44 min Berquist works through Aristotle’s On Interpretation on why truth and falsity belong to statements, not names, then tackles either-or and if-then statements to show which inferences from affirming or denying antecedent and consequent are necessary and which merely probable.

Class 18 2017-03-16 #

Part 1 of 2 · If-Then Arguments, Conversion of Statements, and the First Figure of the Syllogism #

67 min Berquist works through the four combinations of if-then arguments to show which two are necessary, then turns to conversion of statements and the valid moods of the first figure, using dogs, stones, and trees as test cases.

Part 2 of 2 · Reason Knowing Itself; The Second and Third Figures of the Syllogism #

62 min Berquist works through the second and third figures of the syllogism, using dog, animal, stone, and cat as test terms to see which universal premises yield necessary conclusions—then asks what it means for logic to know itself.

Class 19 2017-03-23 #

Part 1 of 2 · Compound Statements, the Definition of Syllogism, and the Kinds of Argument: Syllogism, Induction, Enthymeme, and Example #

62 min Berquist distinguishes simple from compound statements—disjunctive, conjunctive, hypothetical—then defines syllogism against induction, enthymeme, and example, drawing on Aristotle’s Rhetoric and Boethius.

Part 2 of 2 · Two Senses of Induction (God’s Simplicity), the Senses of ‘Body’ and Touch, and the Three Figures of the Syllogism #

66 min Berquist distinguishes two senses of induction and works through Question 3 of the Summa, where Aquinas surveys six kinds of composition to conclude that God is simple, then turns to the valid figures of the syllogism.

Class 20 2017-03-30 #

Part 1 of 3 · Richard Nixon’s Memoirs; How We Know a Statement Is True; Dividing Logic in Two or Three #

41 min Berquist opens with Richard Nixon’s memoirs—his parents, his brother’s death, his mother’s note at the 1953 inauguration—before turning to how logic divides according to the three acts of reason.

Part 2 of 3 · If-Then and Either-Or Syllogisms; the Three Figures; Prior vs. Posterior Analytics #

41 min Berquist works through conditional and either-or syllogisms—why affirming the antecedent proves and denying it doesn’t—then opens Aristotle’s Prior Analytics on why there are exactly three syllogistic figures.

Part 3 of 3 · Aquinas’s Order of God’s Attributes in the Two Summas; Testing Syllogisms in the First and Second Figures #

60 min Berquist compares how the Summa Theologiae and Summa Contra Gentiles order God’s attributes—simplicity, perfection, infinity, immutability, unity—then turns to testing which premise-combinations yield valid syllogisms in the first and second figures.

Class 21 2017-04-06 #

Part 1 of 2 · Demonstration and Dialectic: Form and Matter of the Syllogism, Probable Opinions, Propter Quid and Quia, the Four Questions, and Why Definition Needs Genus and Difference #

69 min Berquist works through Aristotle’s Prior and Posterior Analytics to distinguish demonstration from dialectic, then traces propter quid and quia reasoning through Aquinas’s five ways.

Part 2 of 2 · Definition as Demonstration, the Rule of Two or Three, God’s Ordered Likeness in Creatures, and the Four Tools of the Dialectician #

61 min Berquist works through Aristotle’s Posterior Analytics on definition as compressed demonstration, then turns to the Topics’ four tools of the dialectician, illustrated through mathematical proportion and the analogy of prime matter to substance.

Class 22 2017-04-20 #

Part 1 of 2 · The Four Tools of Dialectic; How Aquinas Orders God’s Attributes in the Two Summas #

63 min Berquist works through Aristotle’s four tools of dialectic from the Topics—probable premises, verbal distinctions, differences, and likenesses—then compares how the Summa Theologiae and Summa Contra Gentiles order God’s attributes.

Part 2 of 2 · Distinctions and Likeness Among the Tools; Why Aristotle’s Metaphysics Book III Begins with Doubting Well #

54 min Berquist closes out Aristotle’s Categories, chapter 12, on the senses of “before” and “in,” then opens Metaphysics Book III with Aristotle’s case for doubting well before answering.

Class 23 2017-04-27 #

Part 1 of 2 · God’s Simplicity, Macbeth’s ‘Fair Is Foul’ and the Two Roots of Error: Speech vs. Things in the Fallacies #

45 min Berquist traces error to two roots—defects of intellect and defects of will—reading Macbeth’s “fair is foul, foul is fair” alongside Aristotle’s Sophistical Refutations and its division of fallacies “from speech” versus “from things.”

Part 2 of 2 · Actual, Potential and Imaginary Double Meanings: Equivocation, Amphiboly, Two Senses of ‘Before’ and How Premises Cause a Conclusion #

66 min Berquist works through Aristotle’s Sophistical Refutations on fallacies of language, separating equivocation and amphiboly from the “potential” fallacies of composition, division and accent, with examples running from “Word of God” to Shakespeare.

Class 24 2017-05-04 #

Part 1 of 2 · Who Is Sylvia? Shakespeare, the Wisdom of Reason, and the Fallacy of Figure of Speech (Seeing Is Not Kicking) #

65 min Berquist reads the song to Sylvia in Shakespeare’s “Two Gentlemen of Verona” for its theological resonances, then turns to Aristotle’s fallacy of figure of speech—why “seeing” grammatically resembles “kicking” but isn’t.

Part 2 of 2 · Figure of Speech in Aquinas: the Trinity as One Principle, Forms Mistaken for Substances, and Why We Err #

55 min Berquist traces the fallacy of “figura dictionis” through Aquinas’s Scriptum, Quaestiones de Potentia, and De Trinitate, showing how treating relational terms as substantial leads to errors about the Trinity and about forms.

Class 25 2017-05-11 #

Part 1 of 2 · Shakespeare’s Definition of Reason, Words Equivocal by Reason, and the Fallacy of the Accident #

58 min Berquist starts from Shakespeare’s line that reason is “the ability for a large discourse, looking before and after” to examine equivocal words, then works through Aristotle’s fallacy of the accident with examples running from Socrates to soft butter.

Part 2 of 2 · The Fallacy of the Accident Continued: Porphyry’s Predicables, De Fallaciis, and What Is First Simply #

46 min Berquist returns to the fallacy of accident, working through Porphyry’s Isagoge and the treatise De Fallaciis alongside Aristotle’s Sophistical Refutations and Categories to sort essential from accidental predication.

Class 26 2017-09-07 #

Part 1 of 2 · Reason Knowing Itself: The Distinction of Distinction and the Fallacy of ‘Simply’ and ‘Somewhat’ (Induction, Rhetoric, Descartes, Hegel, Certainty vs. Dignity of Knowledge) #

51 min Berquist closes his study of fallacies by working out the scholastic distinction between what is known “simply” and “in some respect,” reading from the handouts “Foreword to Logic” and “Reasoning and the Four Kinds of Argument.”

Part 2 of 2 · Act Before Ability, the Best Laws and the Best Life, and Feuerbach’s Infinite Mind: ‘Simply’ vs. ‘Somewhat’ in Metaphysics, Politics, Ethics and Theology #

48 min Berquist works through Metaphysics Book Nine on potency and act, then uses the distinction between what is true “simply” and “in some respect” to expose errors running from materialist cosmology to Feuerbach’s claim that man’s infinite mind is God.