Introduction to Philosophy & Logic (1999) #

A systematic introduction to Aristotelian logic and Thomistic philosophy. These lectures trace the natural progression of human knowledge from sensation to wisdom, examining the essential tools of logical reasoning—definition, division, and syllogistic demonstration—as presented in the works of Aristotle and St. Thomas Aquinas.

44 episodes, about 41 hours

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Classes #

Class 1 #

Part 1 of 3 · Aristotle’s Proemium I: The Natural Desire to Know and Wisdom as Knowledge of Causes #

59 min Berquist opens Aristotle’s Metaphysics proemium, reading “all men by nature desire to know” and tracing knowledge’s ascent from sensation to art and science, on the way to defining wisdom as knowledge of causes.

Part 2 of 3 · The Six Marks of the Wise Man: Wisdom as Knowledge of All and of First Causes #

58 min Berquist works through the opening of Aristotle’s Metaphysics, testing common opinions about the “wise man” to show wisdom is knowledge of the universal and, ultimately, of first causes.

Part 3 of 3 · Wonder, Liberal Knowledge, the Divine Science, and How the Philosopher Must Love Wisdom #

64 min Berquist works through Aristotle’s Metaphysics Book I on why wisdom is the most divine and most honorable science, then asks what it takes to actually love wisdom rather than power, wealth, or freedom in its name.

Class 2 #

Part 1 of 3 · Natural Beginnings of Philosophy: Wonder, the Natural Road, and Axioms #

62 min Berquist locates philosophy’s natural starting points—wonder, the desire to live well, and the road from sense to reason—drawing on Aristotle’s Protrepticus and Metaphysics, the Posterior Analytics, and the handout “An Introduction to the First Road in Our Knowledge.”

Part 2 of 3 · Why Begin from Nature: Beginnings, Order, and Heraclitus on the Common #

64 min Berquist asks why philosophy has to start from nature’s own beginnings rather than private opinion, reading Heraclitus’s fragments on waking, sleeping, and following the common alongside handouts on the “before and after” in reasoning.

Part 3 of 3 · Coming into Philosophy through Reason: Shakespeare’s Exhortation and the Ability for Discourse #

51 min Berquist opens with the natural roots of philosophy—wonder, hope, humility—before turning to reason itself, reading Shakespeare’s “What is a man…” speech line by line to define reason as “the ability for large discourse, looking before and after.”

Class 3 #

Part 1 of 3 · Reason as Ability for Large Discourse, Looking Before and After: Defining Reason #

40 min Berquist works through Shakespeare’s line that reason is “large discourse, looking before and after,” breaking it down term by term as a logical definition in genus and difference.

Part 2 of 3 · The Senses of Before and After, Order, and the Exhortation’s Five Reasons to Use Reason #

58 min Berquist takes Shakespeare’s line “large discourse, looking before and after” from Troilus and Cressida and unpacks Aristotle’s several senses of “before”—in time, in being, in reasoning, in rank—to show what reason itself is for.

Part 3 of 3 · Why Philosophy Requires Reason: Review, Error and Mistake, and Better vs. More Necessary #

64 min Berquist reads Shakespeare’s 49-word “exhortation” defining reason as “large discourse, looking before and after” alongside a text from Aquinas, working out what “before,” “after,” and “order” mean and why philosophy demands the natural use of reason.

Class 4 #

Part 1 of 3 · Thomas’s Proemia: Logic as the Art of Arts and Its Division by the Three Acts of Reason #

64 min Berquist reads Aquinas’s prologues to the Peri Hermeneias and the Posterior Analytics to show why logic is called the “art of arts,” working through the handout “The Proemia to Logic.”

Part 2 of 3 · Logic as Tool and Liberal Art: Ordering Thoughts Through Words #

35 min Berquist works through Aquinas’s commentary on Boethius’s De Trinitate to show why logic counts as an art, and why reasoning can only order its own thoughts through spoken words.

Part 3 of 3 · Name and Speech, and Aristotle on Learning from Pre-existing Knowledge: Syllogism, Induction, Enthymeme, Example #

40 min Berquist distinguishes “name” and “speech” by whether their parts signify on their own, then works through the opening of Aristotle’s Posterior Analytics on learning from prior knowledge, using Euclidean geometry as his example.

Class 5 #

Part 1 of 2 · Why Names Come Before Definition: Equivocal Words, Parts and Wholes, and Two Senses of ‘Its Own’ #

73 min Berquist opens the art of definition by asking why names must be studied before definitions, working through Porphyry’s fivefold distinction of names and the puzzle of “part,” “whole,” and “one’s own.”

Part 2 of 2 · Defining by Names Common to Many Things: Univocal and Equivocal Names, Genus, Species and Difference #

69 min Berquist works through Porphyry’s Isagoge on how things get named and defined, distinguishing proper from figurative speech and univocal from equivocal names, on the way to genus, species, and difference.

Class 6 #

Part 1 of 2 · Porphyry’s Five Predicables: Property, Accident, and Genus vs. Species as Relative Distinctions #

70 min Berquist works through Porphyry’s five predicables, dividing what lies “outside the nature” of a thing into property and accident, then asks whether a lowest species or highest genus exists.

Part 2 of 2 · Genus, Difference, and Lowest Species Reviewed: Why the Division Is Exhaustive, and Are There Lowest Species? #

66 min Berquist returns to Porphyry’s Isagoge to work out how genus, difference, and lowest species share and differ in their definitions, drawing on Aristotle’s Poetics, Posterior Analytics, and Plato’s Meno.

Class 7 #

Part 1 of 3 · Dividing the Categories: Substance, Quality, Relation, and Habitus #

45 min Berquist works through Aristotle’s ten categories as a chain of twofold and threefold divisions, showing how substance, quantity, quality, relation, and six further accidents fall out of what can be said of Socrates or a horse.

Part 2 of 3 · Lowest Species and Highest Genera: Why Being Is Not a Genus #

45 min Berquist asks why division into genus and species doesn’t always bottom out neatly, then shows why “being” itself can’t be a genus—working from Aristotle’s Categories.

Part 3 of 3 · Aristotle’s Ten Categories and Porphyry’s Isagoge: Quantity, Quality, Relation, and the Predicables #

50 min Berquist works through Aristotle’s Categories—substance, quantity, and quality—then turns to Porphyry’s Isagoge and its five predicables as the groundwork for definition and division.

Class 8 #

Part 1 of 2 · Figurative Naming and Names Equivocal by Reason: Synecdoche, Antonomasia, Metonymy, Metaphor, Irony, and the Kept Name #

59 min Berquist works through the five kinds of figurative naming—synecdoche, antonomasia, metonymy, metaphor, and irony—then explains how a common name splits into properly-kept and newly-applied uses in analogous, “equivocal by reason” naming.

Part 2 of 2 · Names Carried Over: Dropping Meaning and Ratios, Analogy, Metaphor in Scripture and Poetry, and Examples #

69 min Berquist tracks how words shift meaning by generalization or by proportion—“passion,” “healthy,” “philosophy”—and separates this analogical naming from metaphor, drawing on Aristotle’s Peri Hermeneias and Aquinas.

Class 9 #

Part 1 of 3 · The Art of Definition I: Definition of a Thing vs. a Name, Full Definition and Encircling, Cause and Effect #

63 min Berquist continues his treatment of definition, distinguishing the definition of a thing from the mere definition of a name, and full definition by genus and species from looser “encircling” definitions by property or effect.

Part 2 of 3 · The Art of Definition II: Substance and Accident, and How to Hunt Down a Definition #

65 min Berquist draws the distinction between substances, defined “by themselves,” and accidents like health and wisdom, defined “as of another,” then lays out three ways to hunt down a definition.

Part 3 of 3 · The Art of Division: Integral and Universal Wholes, Distinction, and the Rule of Two or Three #

44 min Berquist works out what division actually means—splitting an integral whole into its parts versus a universal whole into its kinds—then tests a “rule of two or three” against Plato’s dichotomies and Aquinas’s sevenfold division of the sacraments.

Class 10 #

Part 1 of 3 · Logic of the Second Act: Distinctions, Division, and the Statement #

55 min Berquist moves from the logic of definition to the logic of the statement, reviewing division and distinction before opening Aristotle’s Peri Hermeneias to define statement as speech signifying true or false.

Part 2 of 3 · True and False in the Simple Statement: Saying More or Less Than the Truth, and Contradictories #

45 min Berquist works through the handout “The Art About Statement” and DHB Vol. III to show how a simple statement is true by conforming to things, and false either by adding to or subtracting from that truth—then turns to contradictories.

Part 3 of 3 · Compound Statements and the Square of Opposition #

60 min Berquist works through hypothetical and disjunctive statements, then the square of opposition, reading a handout page (“The Art About Statement,” p. 6) and Aquinas’s commentary on the Posterior Analytics.

Class 11 #

Part 1 of 3 · Logic of the Second Act Wrap-Up, Mr. Anti-Statement, and What Reasoning Is #

52 min Berquist closes out the logic of judgment with the “Mr. Anti-Statement” device and the square of opposition, then opens the logic of reasoning, distinguishing it from guesswork and previewing example, induction, enthymeme, and syllogism.

Part 2 of 3 · Example, Induction and Enthymeme: Arguments Near the Senses #

50 min Berquist works through Aristotle’s example, induction, and enthymeme—arguments that fall short of the syllogism—using Shakespeare, Cicero, and everyday cases like choosing a restaurant or a course.

Part 3 of 3 · The Syllogism, Its Likeness to Calculation, and Dividing the Four Arguments #

58 min Berquist defines the syllogism against calculation, then sorts the four arguments—syllogism, induction, enthymeme, example—by resemblance and by use, with Othello and Aesop as test cases.

Class 12 #

Part 1 of 2 · Three Kinds of Syllogism: The Four Forms of If-Then Speech, the Meno and Euclid #

65 min Berquist lays out Aristotle’s three kinds of syllogism—categorical, hypothetical, and disjunctive—and tests the valid and invalid forms of if-then reasoning against Euclid’s Proposition 6 and Plato’s Meno.

Part 2 of 2 · Form and Matter of the Syllogism: Either-Or and If-Then Syllogisms, Right Opinion, and Proportion #

68 min Berquist distinguishes the form of a syllogism from its matter, then works through disjunctive and conditional syllogisms—showing which of the four if-then patterns are valid and which fallacious, with examples from Euclid, Aquinas, and Plato’s Socrates.

Class 13 #

Part 1 of 3 · The Syllogism: Set of All, Set of None, and the Sixteen Moods of the First Figure #

69 min Berquist works through the sixteen premise-combinations of the first-figure syllogism, using the “set of all” and “set of none” principles to sort valid from invalid, with examples running from animals and plants to dogs, cats, and stones.

Part 2 of 3 · Second Figure Syllogisms, the Power of the Figures, and Why Universal Negatives Convert #

69 min Berquist works through all sixteen premise combinations of the second-figure syllogism, using counterexamples with animal, dog, cat, and stone to show why the figure yields only negative conclusions.

Part 3 of 3 · Conversion and the Second Figure Mixed Cases, Then Nature, Faith and Reason #

70 min Berquist proves the convertibility of universal negatives and works through Aristotle’s second-figure syllogisms, testing valid and invalid forms with animal, dog, and stone before turning to Plato’s Phaedo and Aquinas on faith.

Class 14 #

Part 1 of 3 · Demonstration: Cause, Necessity and Through Itself #

40 min Berquist works through Aristotle’s Posterior Analytics on demonstration as a syllogism that yields necessary knowledge of a cause, distinguishing demonstration propter quid from demonstration quia, with a brief reading from a handout on Shakespeare.

Part 2 of 3 · Dialectic and Sophistical Refutations: Fallacies of Language #

40 min Berquist works through Aristotle’s Sophistical Refutations, dividing the thirteen fallacies into those of language and those of things, with equivocation—drawn from Feuerbach, Scripture, and ordinary speech—as the chief example.

Part 3 of 3 · Fallacies Outside Language: Accident, Secundum Quid and the Meno #

67 min Berquist works through Aristotle’s fallacies of accident and of the simple versus the qualified, then turns to Meno’s paradox and Socrates’ slave-boy demonstration.

Class 15 #

Part 1 of 2 · Syllogism Figures, Wisely and Slow, and the Eight Recurring Forms of Argument #

52 min Berquist works through the third figure of the categorical syllogism and its valid moods, then traces eight recurring argument-forms as they appear in Euclid’s Proposition 1 and Aquinas on the causes of love.

Part 2 of 2 · Analyzing Arguments in Euclid and Aquinas: Main Syllogisms, Continuous Syllogisms, and the Matter of Syllogism #

32 min Berquist works through Euclid’s Elements, Book VII, Propositions 6 and 29, showing how these geometric proofs weave together categorical, hypothetical, and disjunctive syllogisms into single continuous arguments.

Class 16 · Demonstration versus Dialectic: Necessity, Per Se Properties, and Opinion in the Posterior Analytics and Topics #

60 min Berquist works through Aristotle’s split between demonstrative and dialectical syllogisms in the Posterior Analytics and Topics, showing why geometry proves necessity while opinion only reasons toward it.

Class 17 #

Part 1 of 2 · The Dialectician’s Tools: Probable Premises, Senses of Words, and Differences #

64 min Berquist works through the dialectician’s tools from Aristotle’s Topics, comparing dialectical syllogism and induction to rhetoric’s enthymeme and example, then drills equivocal words like “dry,” “liberal,” and “healthy.”

Part 2 of 2 · Seeing Likeness and Proportion, Then Q&A on Places and Comedy #

68 min Berquist explains the fourth dialectical tool—spotting likeness between things far apart—through Plato’s Meno, Euclid, and analogies from physics, Shakespeare, and Scripture, then turns to Plato’s Phaedo to trace Socrates’s a fortiori argument for the soul’s immortality.

Class 18 · Equivocation, “As Such” versus Accident, and Being Simply or in a Certain Respect #

19 min Berquist walks through three fallacies of confusion — equivocal words, what belongs to a thing “as such” versus by accident, and being simply versus in a qualified sense — using lumber becoming a house and marble becoming Michelangelo’s Pietà.