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HoP 487 Showing Good Judgment: The Port Royal Logic

Summary

This episode examines the Port Royal Logic, a seminal 17th-century logic textbook authored by Antoine Arnauld and Pierre Nicole. The work is presented as a quintessential example of Cartesian logic, designed to replace the perceived useless complexities of scholastic logic with a practical tool for educating judgment and thinking well. It explicitly draws on Descartes, emphasizing clear and distinct ideas as a foundation for reliable knowledge and dismissing technical scholastic topics as irrelevant distractions.

The Port Royal Logic positions itself against both scholasticism and empiricist rivals like Gassendi, arguing for the existence of innate ideas and the certainty of truths derived from pure thought, such as the cogito. However, the episode also complicates the straightforward association between Jansenism and Cartesianism, noting that other prominent Jansenists, including Pierre Nicole himself and Blaise Pascal, expressed skepticism or outright rejection of Descartes’ philosophy due to theological concerns.

The discussion delves into specific philosophical contributions of the text, particularly its theory of signs—influenced by Augustine—which distinguishes between material signs (like words as noises) and the spiritual ideas they signify. A significant portion is devoted to the Logic’s controversial equation of propositions with judgments, arguing that forming any complete thought inherently involves an act of affirmation or denial. This view, analyzed through modern scholarship like that of Jennifer Marusich, attempts to resolve problems like hypothetical statements or reports of others’ beliefs by treating them as judgments about judgments.

The episode concludes by reflecting on the Logic’s immense historical influence as a widely used textbook, comparing its impact to that of Porphyry’s introduction to Aristotelian logic. It underscores the work’s enduring significance in the history of philosophy and logic, while humorously noting the podcast’s own role in disseminating philosophical ideas.

Recommendations

Books

  • The Port Royal Logic — The central text under discussion, authored by Antoine Arnauld and Pierre Nicole. Described as the ‘representative par excellence of Cartesian logic,’ it was conceived as a practical textbook to educate judgment and replace scholastic logic.
  • Old and New Logic by Johannes Clauberg — A competing work from 1654 that aimed to provide a definitive statement of Cartesian logic, mentioned alongside Jacques Du Roure’s work as part of the effort to establish a new, useful logic.

Concepts

  • Clear and Distinct Ideas — A Cartesian concept central to the Port Royal Logic. Ideas that are perfectly reliable; anything contained within them can be truthfully affirmed of the subject. They form the foundation for certain knowledge.
  • Theory of Signs — A topic emphasized in the Logic, influenced by Augustine. Explores how material signs (like words as noises) signify spiritual ideas. Contrasted with the Eucharist, where the sign (the host) is actually united with the thing signified (Christ).

People

  • Antoine Arnauld — Co-author of the Port Royal Logic, a Jansenist theologian and philosopher deeply influenced by Descartes, though his Cartesianism was not universally shared among Jansenists.
  • Pierre Nicole — Co-author of the Port Royal Logic, who elsewhere proclaimed himself neutral on Descartes’ philosophy, finding it ‘full of uncertainties and obscurities.’
  • Stephen Nadler — An expert on early modern philosophy cited for questioning the assumed tight link between Jansenism and Cartesianism, suggesting Arnauld was more the exception than the rule.
  • Jennifer Marusich — A modern scholar whose interpretation is cited to resolve the Logic’s controversial claim that propositions are judgments. She suggests complex thoughts involve judgments about judgments.
  • Nicolas Malebranche — A proponent of occasionalism mentioned as the subject for the next episode of the podcast.

Topic Timeline

  • 00:00:58 — Introduction to the Port Royal Logic and its Cartesian context — Peter Adamson introduces the episode’s focus on the Port Royal Logic, a 17th-century textbook by Antoine Arnauld and Pierre Nicole. He frames it within the broader Cartesian reaction against overly complex and useless scholastic logic, highlighting the humanist and Cartesian critiques that preceded it. The Logic is presented as an attempt to create a practical, intuitive logic for use in Cartesian science.
  • 00:05:16 — The purpose and audience of the Port Royal Logic — The episode details the origins of the Port Royal Logic as a textbook written for a young nobleman, originally intended to be a quick project but expanding into a major work. Its stated aim is to ‘educate our judgment’ and ‘think well,’ explicitly excluding material deemed not necessary for that goal. The authors criticize other logicians for indulging in pointless discussions in logic, mathematics, and metaphysics, advocating instead for a focus on useful, concrete examples.
  • 00:07:55 — Clear and distinct ideas as the foundation of logic — The discussion centers on how the Port Royal Logic adopts the Cartesian notion of clear and distinct ideas as the bedrock of reliable knowledge. It connects this to the analysis of propositions (subject-predicate statements). Truths contained within a clear and distinct idea can be affirmed with certainty. The episode questions why logic is needed if we have such ideas, suggesting that logic allows us to combine them into syllogisms to derive further conclusions, though error more often stems from false premises than invalid reasoning.
  • 00:10:03 — Debate with empiricism and the role of sensation — Arnauld and Nicole address the empiricist challenge, particularly from Gassendi, who claimed all knowledge comes from the senses. They counter with examples like the concept of a ‘chiliagon’ (a thousand-sided figure) to demonstrate the mind’s capacity for ideas not derived from sensation. They cite Augustine to acknowledge the role of sensation (a weakness from original sin) but uphold the superior certainty of truths known through pure thought, such as the cogito (‘I think, therefore I am’).
  • 00:11:12 — Questioning the link between Jansenism and Cartesianism — While the Port Royal Logic seems to confirm a strong link between Jansenism and Cartesianism, the episode cites historian Stephen Nadler and other Jansenist figures to complicate this picture. Key Jansenists like Le Maistre de Sacy and Blaise Pascal rejected Descartes, and even co-author Pierre Nicole expressed neutrality, calling Descartes’ philosophy ‘full of uncertainties and obscurities.’ This suggests Arnauld’s strident Cartesianism was more exceptional than representative within the Jansenist movement.
  • 00:13:50 — Theological concerns and the theory of signs — The episode highlights the theological underpinnings of the Logic, such as its use of Protestant arguments about the Eucharist as examples of bad logic and its final emphasis on faith as a source of knowledge alongside reason and sensation. This theological interest inspires a focus on the theory of signs, influenced by Augustine. Signs (like words) are material entities that signify spiritual ideas. The authors contrast this with the Eucharist, where the host is not merely a sign but is united with Christ.
  • 00:17:24 — Propositions as judgments: a controversial doctrine — A deep dive into one of the Logic’s most discussed and problematic doctrines: the equation of propositions with judgments. The text defines judging as the mind affirming or denying a connection between ideas, implying that merely entertaining a thought (like ‘a giraffe is in the kitchen’) constitutes a judgment. The episode outlines the obvious problems this poses for hypothetical statements or reporting others’ beliefs. It presents Jennifer Marusich’s interpretive solution: in complex cases, we are making a judgment about a judgment.
  • 00:20:40 — Historical influence and conclusion — The episode concludes by reflecting on the Port Royal Logic’s massive historical influence as a widely used textbook throughout the 18th and 19th centuries, comparing its impact to Porphyry’s introduction to Aristotelian logic. It humorously notes that a podcast might be the only way to reach a wider audience. The discussion sets the stage for the next episode, which will cover the occasionalist philosopher Nicolas Malebranche.

Episode Info

  • Podcast: History of Philosophy Without Any Gaps
  • Author: Peter Adamson
  • Category: Society & Culture Philosophy
  • Published: 2026-02-22T09:27:04Z
  • Duration: 00:21:58

References

Podcast Info

Transcript

[00:00:00] Hi, I’m Peter Adamson and you’re listening to the History of Philosophy podcast, brought

[00:00:18] to you with the support of the Philosophy Department at King’s College London and the

[00:00:21] LMU in Munich, online at historyofphilosophy.net. Today’s episode, Showing Good Judgment,

[00:00:28] the Port Royal Logic.

[00:00:58] were in my own handwriting, I couldn’t understand any of it, because I’d forgotten everything

[00:01:02] in the intervening months. Fortunately, since then I haven’t needed most of what we learned.

[00:01:08] Yet, I do not regret taking the class, because to do philosophy seriously, you really need

[00:01:13] to have mastered some logic. It’s useful just to know what all the symbols and notations

[00:01:18] mean, and more profoundly to be able to analyze an argument with full rigor. And as it happens,

[00:01:23] I’ve wound up being pretty interested in Aristotelian logic, and very interested,

[00:01:28] in the transformation of his system at the hands of Avicenna and other logicians in the

[00:01:32] Islamic world.

[00:01:34] Apart from that, I think my experiences with logic have been pretty typical for a philosopher

[00:01:38] who does not work directly in philosophy of logic. On the one hand, it’s useful to have

[00:01:44] a grasp of the basics. On the other hand, once a card-carrying logician gets you in

[00:01:48] their grasp, they’re going to go beyond what is merely useful to explore logical issues

[00:01:53] more deeply, because the logicians are interested in these problems for their own sake.

[00:01:58] This pattern is not specific to modern-day analytical philosophy. It actually happened

[00:02:03] in the Islamic world, when logicians writing in the wake of Avicenna started to contemplate

[00:02:08] issues that have no obvious application, like happens when a proposition contains an impossible

[00:02:13] subject term, as in, square triangle has three sides. In India, the Nyaya school began as an

[00:02:20] effort to understand Vedic literature, but soon enough started debating technical issues around

[00:02:25] argumentation theory. In Warring States, China, it was the first time that an argumentation theory

[00:02:28] was used. In China, the early Moists set forth utilitarian ethical and political doctrines,

[00:02:33] but the later Moists composed texts that are purely about language and reasoning. The idea

[00:02:37] was presumably to use these logical tools to defend the earlier doctrines, but the later

[00:02:42] Moist writings barely even mention this.

[00:02:46] And so it was also with scholastic logic. One of the biggest complaints made by enemies

[00:02:51] of the scholastics was that their treatments of logic had become far too complicated and

[00:02:56] arcane to be of any use.

[00:02:58] We see this especially in humanist writers like Lorenzo Valle and Juan Luis Vives, who mocked the

[00:03:05] schoolmen for investigating the implication of such nonsense statements as,

[00:03:09] only any non-donkey belonging to this same man begins contingently to be black.

[00:03:15] These humanists also disliked the grotesque, highly artificial Latin used in university

[00:03:21] text on logic. But their more principled complaint was that the enterprise was largely useless.

[00:03:27] We find that the use of language and reasoning in the study of logic is not necessarily the

[00:03:28] only reason for this. We find powerful echoes of this attitude in Cartesian philosophy. Descartes

[00:03:32] himself said that scholastic logic corrupts good sense rather than increases it, and his admirers

[00:03:38] set out to replace that logic with something more fit for purpose. This wasn’t going to be the

[00:03:44] rhetorical art proposed by the humanists, but a simpler and more intuitive logic that could be put

[00:03:49] to use in Cartesian science. Descartes made initial efforts in this direction, as we see with his interest in method.

[00:03:58] Various successors then competed to provide the definitive statement of Cartesian logic.

[00:04:03] In 1654, Johannes Clauburd brought out his Old and New Logic, whose very title indicates his agenda.

[00:04:11] In the same year, Jacques Duhour published a work covering both scholastic and Cartesian logic,

[00:04:17] and proclaiming the latter more useful. Duhour then produced an abridgment of true philosophy

[00:04:23] that drifted even further towards Descartes and away from Aristotelianism.

[00:04:28] But the competition to produce the standard Cartesian logical text was won by Antoine Arnold

[00:04:34] and Pierre Nicolle, whose treatise was named after the stronghold of the Jansenists,

[00:04:39] The Port Royal Logic. It was first published in 1662, and went through four revisions,

[00:04:45] with the final version appearing in 1683. It has been called the representative par excellence of

[00:04:52] Cartesian logic, and for good reason, as we’ll see shortly. But the work does not break completely with

[00:04:57] scholastic tradition. It covers most of the same topics that would be found in a university

[00:05:01] textbook of logic, and even says some of the same things about those topics. One difference, though,

[00:05:07] is that Arnold and Nicolle try to avoid the temptation to explore logical questions

[00:05:12] that go beyond the strictly useful. As they explain in a preface,

[00:05:16] the Port Royal Logic was conceived as a textbook for a young nobleman, here unnamed,

[00:05:22] though we know that they are referring to Charles Honoré d’Albert, whose aristocratic father had

[00:05:26] translated Descartes’ Meditations into French. Originally, Arnold and Nicolle wanted to dash the

[00:05:33] thing off in a day. In the end, the project proved more daunting, and it took them all of four or five

[00:05:38] days to complete a first draft. That was then expanded to form the published version. For our

[00:05:44] two authors, the purpose of logic is, “…educating our judgment and making it as precise as possible,”

[00:05:50] or as they concisely put it later on, “…the aim of logic is to think well.” Anything that turns out to be a

[00:05:56] necessary for that goal is in theory excluded. Some more technical material is included,

[00:06:02] because it had always been standard in scholastic logic, but our authors invite their readers to

[00:06:06] skip them. They also use concrete examples drawn from the sciences to illustrate logical points,

[00:06:12] to bring home that this is a logic that is to be put to real use.

[00:06:17] Other authors are criticized for failing to do this and for indulging in pointless discussions

[00:06:21] that will never lead anywhere, including in other fields like mathematics and metaphysics.

[00:06:26] People are not born to spend their time measuring lines, examining the relations

[00:06:31] between angles, or contemplating different motions of matter. The mind is too large,

[00:06:35] life too short, time too precious, to occupy oneself with such trivial objects.

[00:06:42] When it comes to many familiar questions of metaphysics, like whether the created world

[00:06:46] could be eternal, they say that “…the safest thing is to get rid of them as quickly as possible,

[00:06:50] and after studying, cursorily, how they arise, to resolve in good faith to ignore them.”

[00:06:56] This all sounds extremely Cartesian. The Port-Royal Logic borrows the impatient tone he takes with

[00:07:02] the scholastics, as well as the confident tone he adopts when describing his own methods.

[00:07:07] More than that, it explicitly announces, towards the beginning, that it will be drawing on Descartes,

[00:07:13] whose mind is as sharp as those of others are confused.

[00:07:17] So it is that canonical items on the usual logical syllabus,

[00:07:21] like the theory of the ten categories, the five types of predicate, and the use of standard

[00:07:26] terms or topics to devise arguments, are dismissed as a waste of time, in favor of clear and distinct

[00:07:32] ideas. As we saw last time, when talking about his views on free will, Arnold thinks it is impossible

[00:07:39] to reject such ideas. We find that point in the Port-Royal Logic as well. Arnold and Nicolle

[00:07:45] write that “…no marks are necessary to recognize the truth but the very brightness which surrounds

[00:07:51] it, and to which the mind submits, persuading it in spite of itself.”

[00:07:55] They connect the notion of clear and distinct ideas to the chief concern of Aristotelian logic,

[00:08:01] which is the analysis and combination of sentences in which a predicate is applied to a subject.

[00:08:07] In the case of an unclear and indistinct idea, like, pleasure is good, it is an open question

[00:08:12] whether the predicate, good, applies truly to the subject, pleasure. By contrast, everything

[00:08:18] contained in the clear and distinct idea of a thing can truthfully be affirmed of it. If, for example, we

[00:08:25] indistinctly grasp God as being infinite, then we can be sure that infinity is a predicate that truly

[00:08:30] belongs to God. These, by the way, are my examples, but I think that Arnold and Nicolle would approve

[00:08:36] since they put so much emphasis on the use of examples when explaining logic.

[00:08:42] Since clear and distinct ideas are perfectly reliable, we might wonder why we need anything

[00:08:46] else? Why not just stick with the propositions that spell out the content of these ideas

[00:08:51] and suspend judgment about everything else?

[00:08:55] …

[00:08:55] reason would be that we can make progress by combining clear and distinct ideas to produce

[00:09:00] further conclusions. I’d better give another example. Any Cartesian would agree it is a clear

[00:09:05] and distinct idea that God is infinite, and that no body is infinite. So we can combine these two

[00:09:12] propositions in a syllogism to yield the conclusion God is not a body. Admittedly, that is pretty easy

[00:09:18] if not trivial, but the syllogisms do get more complicated than that, which is why we need logic.

[00:09:23] Though, actually, Arnaud and Nicolle say that it is pretty rare for people to make mistakes simply

[00:09:29] because they reason invalidly. Usually, error results from false premises, not failures of

[00:09:35] logic. Maybe this is one reason the Port-Royal logic was so popular. It constantly reassures

[00:09:40] you that the stakes are pretty low, and that the more difficult and technical parts probably aren’t

[00:09:45] going to matter at all. Another reason we cannot make do with nothing but clear and distinct ideas

[00:09:51] is that we also get knowledge from sensations.

[00:09:53] Some contemporaries would go further. There are no innate clear and distinct ideas,

[00:09:58] perhaps no innate ideas at all, and in fact all our knowledge derives from sensation.

[00:10:03] Most of us would think here of the British empiricists, like Locke, Barclay, and Hume,

[00:10:08] but when the Port-Royal authors think of empiricism, they have in mind a target who

[00:10:12] is, for them, closer to home, Gassendi and his followers. Arnaud and Nicolle cite Augustine

[00:10:19] for the idea that we do depend on sensation for knowledge, this being a weakness in

[00:10:23] our minds inflicted by original sin. But we often have conceptions not derived from sense experience,

[00:10:29] something they illustrate with the chiliagon, meaning a thousand-sided geometrical figure,

[00:10:34] though it sounds more like a lack of supplies at a Mexican restaurant.

[00:10:38] Examples like the chiliagon show that Gassendi was wrong to say that

[00:10:42] nothing is in the mind that was not earlier in the senses, and in fact, things we discover through

[00:10:47] pure thought are if anything more certain than what we can learn from sensation.

[00:10:51] Just take our knowledge that we,

[00:10:53] exist, about which we can be certain, given the undeniable inference, I think, therefore, I am.

[00:11:00] If there were any doubt about the Cartesian credentials of the Port-Royal logic,

[00:11:03] that example should banish them. It seems, in fact, that this textbook proves, beyond doubt,

[00:11:08] the close connection between Jansenism and Cartesianism.

[00:11:12] This association, which I already mentioned in the last episode, is also apparently confirmed

[00:11:17] by witnesses of the time, like one who said in 1690 that there are very few Jansenists who are

[00:11:23] not Cartesians. But Stephen Nadler, an expert on early modern philosophy in general, and Cartesianism

[00:11:29] in particular, has questioned this judgement. Given our current preoccupation with logic,

[00:11:34] we might put Nadler’s point by saying that such statements illicitly infer a universal

[00:11:39] judgement from a particular case. Clearly, Arnaud was powerfully influenced by Descartes,

[00:11:44] the Port-Royal logic wears that influence on its sleeve,

[00:11:47] and we already saw that his whole thought is shot through with Cartesianism. But as it turns out, a

[00:11:52] lot of other members of the Jansenist movement had their doubts. One friend of Arnaud warned him not

[00:11:58] to embrace Cartesianism because of the theological problems it would entail. For instance, strict

[00:12:03] dualism raises doubts about bodily resurrection and transmission of original sin through physical

[00:12:09] inheritance. One important Jansenist named Le Maistre de Sacy actually rejected Descartes in

[00:12:15] no uncertain terms, writing, What new ideas can I obtain of the grandeur of God when I am told that

[00:12:21] the sun is a massive mass of the sun? The sun is a massive mass of the sun. The sun is a massive mass

[00:12:22] of the sun. The sun is a massive mass of the sun. The sun is a massive mass of the sun.

[00:12:22] He was no fan of Aristotle either, whom he compared to a thief who had usurped power within

[00:12:31] the church. But for him, Descartes was like a thief who has killed another thief and made off with his

[00:12:36] spoils. We might assume that Pierre Nicolle, Arnaud’s co-author in writing the Port-Royal

[00:12:43] logic, must have been a staunch Cartesian. But elsewhere, he proclaimed himself neutral on the

[00:12:47] merits of Descartes, given that his philosophy was full of uncertainties and obscurities.

[00:12:52] When we recall that another Jansenist, Pascal, included a note in his Pensée stating simply,

[00:12:59] Descartes, useless and uncertain, we realize that Arnaud may have been more the exception

[00:13:03] than the rule in being a stridently Cartesian Jansenist. If so, then a devotion to Descartes

[00:13:10] is not the only characteristically Arnaudian feature of the port-royal logic. I already

[00:13:15] mentioned that it cites Augustine, which is another sign of his handiwork, and more generally,

[00:13:20] theological concerns are not hard to detect in the work. With scarcely disguised glee,

[00:13:26] the logic offers Protestant reasoning about the Eucharist as an illustration of bad logic.

[00:13:32] These heretics thought that the host does not really become Christ’s body in the Catholic Mass,

[00:13:37] giving the argument that, when he said, this is my body, at the Last Supper, the word this refers

[00:13:42] to bread, not body. This argument is dispatched with ease, on the grounds that the word this

[00:13:48] is an ambiguous or confusing argument.

[00:13:50] Thus, when Augustus Caesar said,

[00:13:54] At the end of the port-royal logic, theological concerns again come to the fore,

[00:14:11] as we discover that there is another source of knowledge alongside sense experience and clear

[00:14:15] distinct ideas. There’s also faith, which is the most powerful conviction we

[00:14:20] can have, but never conflicts with other sources of our knowledge.

[00:14:24] In one of several clues that Pascal had some input in the writing of the logic,

[00:14:29] emphasis is put on faith in miracles, and the Protestants, called the heretics of our time,

[00:14:34] are again attacked, in this case for their skepticism concerning the miracles of the saints.

[00:14:40] The work concludes with an even clearer sign of indebtedness to Pascal, as faith is justified

[00:14:45] on the grounds that it is more rational to wager for the existence of God than against.

[00:14:50] Theological concerns seem to have helped inspire a particular focus in the port-royal logic

[00:14:55] on one topic that looks more relevant to philosophy of language, the theory of signs.

[00:15:01] A sign is, of course, something that signifies something else. This could be a literal sign,

[00:15:06] like a placard with a picture of a crossed-out cigarette. It could be linguistic, like an

[00:15:11] attendant on a plane telling someone who’s about to light up, hey, this is a no-smoking flight.

[00:15:15] Or even a gesture, like a wagging of the figure at someone who fishes out a lighter and a pack

[00:15:20] of cigarettes. All three are signs of the idea of not smoking. But as Augustine pointed out in

[00:15:27] a treatment of this issue that influenced the logic, not everything is a sign. A rock is just

[00:15:32] a rock, unless of course someone decides to use it to signify something. Of particular interest

[00:15:38] to our authors are signs in the form of spoken words, which in themselves are just noises.

[00:15:43] With regard to this material level, speaking is common to humans and parrots, as Arnaud and

[00:15:49] Nicolle say in a companion text on grammar, called of course the Port Royal Grammar. But

[00:15:55] when humans use these noises, they are signifying things at the spiritual level, namely their own

[00:16:00] ideas. All this is important to the context of logic, because the terms used in a proposition

[00:16:06] signify either things or ideas. For instance, in the statement giraffes are not rocks, the word

[00:16:12] giraffes refers to giraffes, the word rocks refers to rocks, and the words are not signify the idea

[00:16:19] of negation.

[00:16:19] None of this sounds particularly religious, apart from the use of Augustine. But as it turns out,

[00:16:25] Arnaud and Nicolle wrote yet another work together, on the Eucharist, in which they argue that the

[00:16:30] sacramental host is not just a sign of Christ, as the Protestants claim. That is because in this

[00:16:36] miracle, the spiritual Christ is actually united to the material body of the bread. This in contrast

[00:16:42] to the case of human language, where the material noise of words does merely signify a spiritual

[00:16:47] concept.

[00:16:49] This brings us to the aspect of the port-royal logic that may have received the most attention

[00:16:53] in modern scholarship. It stands to reason that just as words refer to simple concepts or things,

[00:16:59] so entire sentences should refer to complex ideas. Thus the sentence, a giraffe is in the kitchen,

[00:17:05] would call to mind the idea of a giraffe being in the kitchen. But it needn’t do any more than that.

[00:17:11] One could simply entertain this idea without actually having any opinion

[00:17:15] as to whether there is in fact a giraffe in the kitchen, or at least,

[00:17:19] so you would think. But the port-royal logic seems to take a different view.

[00:17:24] It apparently claims that the complex idea, expressed in a sentence,

[00:17:28] always involves making a judgment. So whenever you think a giraffe is in the kitchen,

[00:17:33] you have to be asserting that there is a giraffe in the kitchen.

[00:17:36] This seems to follow from their definition of judgment, which reads in part,

[00:17:40] Judging is the action in which the mind, bringing together different ideas,

[00:17:44] affirms of one that it is the other, or denies of one that it is the other.

[00:17:49] The

[00:17:49] point being that as soon as you have brought together two ideas, like giraffe and being in

[00:17:53] the kitchen, you’ve already made a judgment that affirms a connection between the two things,

[00:17:57] or denied it. In keeping with this, the text seems to use the terms proposition and judgment

[00:18:03] as if they were synonymous, because every time you think of a proposition, you are making a judgment.

[00:18:09] Some interpreters have found it hard to believe that this is what the authors of the logic really

[00:18:13] want to say, because it causes so many problems. The most obvious is the one I just mentioned,

[00:18:19] one can understand a certain statement without taking a view on it. Suppose my friends tell me

[00:18:24] there is a giraffe in the kitchen, and I suspect they’re just teasing me, but I’m not sure, because

[00:18:28] after-all, my door is always open to giraffes, my door is unusually tall. And there are other

[00:18:34] problems, some of which are more technical. For instance, suppose I’m trying to refute my friends,

[00:18:39] and say, if there were a giraffe in a kitchen, I would already hear it making dinner,

[00:18:44] but I don’t hear anything, so there is no giraffe in the kitchen. In this argument,

[00:18:49] we have a so-called hypothetical premise where I say what would follow if there were a giraffe

[00:18:54] in the kitchen. Clearly, when I propose this possibility, I’m not judging that it is true.

[00:19:00] To the contrary, it’s part of an argument designed to show that it is false.

[00:19:04] Or here’s a more straightforward case. If I say, my friends must be crazy, they believe there is

[00:19:09] a giraffe in the kitchen, then I’m using there is a giraffe in the kitchen to express what they

[00:19:14] are judging, not what I am judging. In my own judgment, the most compelling solution is provided

[00:19:20] by Jennifer Maruschich. She suggests that the Port Royal logic means what it says and that it

[00:19:25] really does equate propositions with judgments. But that is only the most simple case in which

[00:19:30] we straightforwardly affirm or deny something. In more complicated cases, as when we merely

[00:19:35] entertain something, propose it hypothetically, or say what someone else thinks, we are actually

[00:19:40] making a judgment about a judgment. This is clearest in the

[00:19:44] last case.

[00:19:44] In the last example, where I say that my crazy friends are making a judgment about a giraffe,

[00:19:48] which in my view is false. And I myself am making a judgment too, namely that they believe this

[00:19:54] crazy thing about a giraffe. It works for the other cases too. If I were merely entertaining

[00:19:59] a proposition, I could be judging that the judgment in question may be either true or false,

[00:20:04] but I’m always making some judgment or other. As Maruschich puts it,

[00:20:09] Once one holds that forming a complete thought of the form S is P is a matter of judging that

[00:20:14] the ideas of S and P agree, it becomes possible to explain other, more complex thoughts in

[00:20:19] terms of the basic case.

[00:20:22] While this is an interesting philosophical issue in its own right, it’s also historically

[00:20:26] significant. John Locke seems to have had a similar view, for instance, and more generally

[00:20:31] any teaching that could be found in the Port Royal logic was going to find its way to a

[00:20:35] wide readership. It has been called the most influential general education textbook of

[00:20:40] the 18th and 19th centuries. It was, to give just one story.

[00:20:44] I’m reminded here of the late ancient Platonist Porphyry, who achieved a spectacularly wide

[00:20:59] readership, lasting the better part of a millennium, by writing a very short introduction

[00:21:03] to Aristotle’s logic. As publishers nowadays are well aware, works of individual and idiosyncratic

[00:21:09] genius are great, but they don’t sell nearly as well as a useful textbook.

[00:21:14] In fact, I can hardly think of a way to communicate philosophical ideas to an even wider audience,

[00:21:19] unless one were, perhaps, to produce a podcast. For example, a podcast that has covered important

[00:21:24] and influential French thinkers like Descartes, Elizabeth of Bohemia, Cassandre, and Arnaud.

[00:21:30] After which I guess one would need to move on to the greatest proponent of occasionalism,

[00:21:34] Nicolas Malebranche. Yeah, someone should really cover him on a podcast.

[00:21:39] Maybe an occasion will arise next time, here on the History of Philosophy, without any

[00:21:43] gaps.

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