Scholastic Logic and Cartesian Logic
2018; The MIT Press; Volume: 26; Issue: 5 Linguagem: Inglês
10.1162/posc_a_00287
ISSN1530-9274
Autores Tópico(s)Medieval and Classical Philosophy
ResumoAs Roger Ariew shows, one of the most fascinating challenges for the authors trying to create a Cartesian complete course on philosophy was coming up with a Cartesian Logic based on the existing texts of the master (Ariew 2014). Were the few simple rules from the Discourse on Method the “logic” of Descartes? Were the Rules for the Direction of the Mind “logic”? How can we even have a logic without syllogism? When looking at the authors studied by Ariew one finds that the best that they could come up was adding some Cartesian elements on what remains basically a traditional Aristotelian Logic. It seems that there was no Cartesian Logic after all.I want to show here that Cartesian Logic is something else, not exactly “Logic” in the way that was taught in the first year of college, but something meant to replace Aristotelian Logic once we have done away with syllogism. A treatise such as the Rules for the Direction of the Mind belongs to a new genre, one that comes out of the transformation of Aristotelian Logic in the early seventeenth century. I call this genre the “Art of discourse.” In the Cartesian corpus the most complete incarnation of this genre is to be found in the (incomplete) Regulae; the preface written for the Essays of 1637, the Discourse on Method, while containing some elements of the art of discourse such as the famous “rules,” remains a preface and not a systematic treatise.While the textual sources of Descartes’s Regulae and its relationship with antique or Renaissance authors have been well scrutinized by Cartesian scholarship, its immediate context, which is that of the early seventeenth-century treatises of Logic, is not well known. This is understandable because the topic itself is very difficult: what Renaissance Logic and early seventeenth-century Logic is remains hard to master, in spite of some eminent research done by Renaissance scholars ever since Die Logik der Neuzeit of Wilhelm Risse (Vasoli 1968, Jardine 1974, Gilbert 1960, and others).1 However, this is a project that needs to be done if we want to understand the motivations of Descartes’s text—that is, not so much the tradition on which he draws and in which we are to place the Regulae, but rather the tradition against which it reacts. Marion’s edition and early work on the Regulae remains the only extensive study on the Aristotelian sources of the text (Marion 1975; Marion and Armogathe 1977; Marion 1978). Marion looked at the Regulae as a direct confrontation with Aristotle, which, as necessary as it is, may give the impression that Descartes was arguing directly against Aristotle, bracketing the entire Aristotelian tradition. The only extensive study on the immediate context of the Regulae is that of André Robinet, which traces, as he puts it, an axis, understood as a continuity of thinking, between Pierre de la Ramée and Descartes, and inscribes Descartes in the Ramist current that traverses the Northern half of Europe in the sixteenth century (Robinet 2000).2 This reconstruction definitely has its merits and one can certainly recognize elements of “Ramism” in the Regulae if one is set to look for them. The conceptual language of the Regulae, terms such as ingenium, invention, deduction, mathesis universalis, and method, lead directly to the Ramist vocabulary.However, one should be careful when presenting Descartes as a representative of something, in the continuity of something, or on a certain “axis,” because he always presented himself in opposition with everyone. Descartes has constantly criticized “the dialecticians” and his adversaries are not only the Aristotelians that he later thought to replace, but also some of the moderns. Anti-Aristotelians such as Pierre de la Ramée are rather to be seen as rivals of Descartes, as figures that he would be susceptible to oppose as much as he opposed the Aristotelians. Descartes would not have seen himself as another Ramus, but as a new Ramus.What counted as Logic for Descartes was foremost the Jesuit Logic that was taught in schools such as the Collège de La Flèche. My purpose is to show that Aristotelian logic in the early seventeenth century was already understood not as an instrument that forms automatisms of thinking to be used by other sciences, and not as a science of demonstration centered on the Posterior Analytics; an “art of discourse,” understood in the perfectly Cartesian sense of directing one’s ingenium in the search of the truth. It is this logic, wholly Aristotelian in its constitutive elements, but defined in a non-Aristotelian way as the art of discourse, that Descartes has in mind when he sketches his own Rules for the direction of the mind.The Regulae arrive at an important moment in the history of Logic. Aristotelian Logic used to be a preparatory discipline, the first thing taught in the Faculty of Arts or in the first year of college as an instrument that teaches the student how to give proper scientific demonstrations when he would be faced with the sciences of real things, such as physics, metaphysics, or medicine. Seventeenth-century logic becomes a science of the operations of the mind, a critique of reason, having as its object the proper scientific discourse. The art of discourse has been associated by scholars with more “innovative” strands of the Nordic Renaissance: either Ramism, Philippo-Ramism, Baconianism, or Northern Italian discussions of method. The second point I want to make is that this evolution of Logic is not a criticism of Aristotelian Logic or something that comes from the outside of the Aristotelian tradition, as the lecture of some novatores has led us to believe. If we look at more conservative strands, such as Jesuit philosophy, one can see this transformation of Logic taking place within the Aristotelian tradition itself. Jesuit Logic was also an “art of discourse” and it developed into one not under the influence of Ramism, but as an organic growth from within the medieval tradition. The art of discourse in the seventeenth century is simply what seventeenth-century Logic is meant to be, and its function is to direct the mind, regardless of whether the material it deals with comes from Aristotle, Melanchton, Pierre de la Ramée, or Descartes.According to Wilhem Risse’s monumental Bibliographia logica (1965), there are some 20,000 works on Logic published during the sixteenth and the seventeenth centuries throughout Western Europe. The breadth of this material defies any effort of systematization. I propose to start getting a sense of the picture from one of the most influential logicians of the century, Franco Burgersdijk (1590–1635), professor at the University of Leiden in the 1620s when Descartes was writing the Regulae, and later rector of the same university (see Bos and Krop eds. 1993). Burgersdijk’s Logic had a tremendous success in England and was taught in universities until well into the eighteenth century.In his Institutionum logicorum libri duo (1626), where he proposes a quite innovative “system” of Logic, he divides the recent logicians into three classes or three currents, each with its own faults. In the first class there are those that follow Aristotle step by step (kata podas). They put together Aristotle’s Organon from his writings, extract the same principles from them, follow the same method, and even give the same examples. They produce merely Introductions to Aristotle (Isagoge) that are useful books for understanding Aristotle’s doctrine but cannot count as systematic Institutions of Logic. Aristotle’s books are admirable taken individually, says Burgersdijk; but it is difficult to extract an Organon from them. There are problems of edition and transmission of texts: we do not know the order in which Aristotle has written or edited them, and they are obviously written in different occasions and for different purposes. In short, putting Aristotle’s logical books together in one volume, as some recent authors do, will do nothing to bring us closer to a complete Logic.What would then be a complete Logic? It should treat of four “instruments”: definition, division, syllogism, and method, the landmark tetrad of Burgersdijk Logic. Aristotle and his followers only speak of one of them, syllogism, and even of this one they give an incomplete treatment, ignoring some of its forms. Here Burgersdijk invalidates the entire project of the Aristotelian courses on philosophy that were starting to be developed in Jesuit colleges at the turn of the century. Not only so, but he invalidates the Aristotelian corpus itself—very little of the material found in Aristotle’s books pertains to Logic proper, he says. These reproaches are by then well-known: ever since Pierre de la Ramée, logicians have created their own anti-Aristotelian tradition. In the seventeenth century, for Burgersdijk at least, Logic is a project that needs to be entirely redone.The second class of logicians is headed by Petrus Ramus, “a man as elegant as he is learned, but audacious and injurious towards antiquity.”3 Burgersdijk praises Ramus for having rightfully raised himself against the depraved mores of the century, that of treating Aristotle as if it were a religious summa. But wanting to correct the Scylla of this habit, he fell into the Charybdis of barbarism. Ramus drew from whatever anti-parepatetic sources he could: Cicero, the Stoics, plus some recent humanists such as Jean-Louis Vivès, Lorenzo Valla, and Rudoph Agricola. Although not without merits, his work is short, obscure and “mutilated,” and “often strays away from the truth.” Its obscurity comes from the immoderate use of dichotomies and tables; they are supposed to help memory but their overuse hinders it. As to the content, Ramist Logic has only two disciplines: method and use. He ignores the proper uses of definition and division that are necessary when apprehending the notions known per se, and his treatment of syllogism is faulty. In the end, compared to the true system of Logic, that of Burgersdijk, Ramus is even more insufficient than Aristotle.A third class of logicians is headed by Bartholomäus Keckermann, for which Burgersdijk has kinder words. Keckermann put together the doctrines of Aristotle and Ramus: from Aristotle he took the material, from Ramus the method, and what he did not find in one he found in the other. This class of syncretic logicians (no names are given) is superior to the two preceding ones, but Burgersdijk goes nevertheless through a detailed analysis of the faults of Keckermann. The main argument is, again, that he ignores the crucial instruments of definition and division. Without these two operations, Logic cannot accomplish its function, which is, Burgersdijk tells us, to direct the mind on the right path and to correct its vices. There are two original vices of the mind in the very first apprehension of things that Keckermann’s Logic does not address: one fault comes about when the mind does not grasp the essence of the thing adequately and this needs to be corrected through definition. The other fault comes about when the mind does not correctly individuate the parts that belong to the thing and this is corrected through division. In the end, Keckermann is, him too, at fault simply because he is not Burgersdijk. But he is nevertheless praiseworthy as the proponent of the most complete systematic Logic we have so far.Seen through the eyes of the famous Dutch professor, early seventeenth-century Logic is not a multi-secular rigid discipline but a science yet to be written. In this project, we are presented with competing strands, different solutions, based on two main references: Aristotle and Ramus. More importantly, this science has a goal: directing the mind on the right path towards the truth and correcting its vices. Logic teaches how to correctly apprehend individual things and how to relate them in a discursive chain, following a method. Put in this way, one can clearly see Descartes’ Regulae inscribed in this project.My interest is in showing that Aristotelian logic is not the caricature that Burgersdijk presents us with, and not only that. If Aristotelian logic were just an effort of interpreting Aristotle or a treatise on syllogism, it would not be a contender for the same project that Burgersdijk or Descartes have. Late Aristotelian logic is one of the alternatives on the table, part of the same project of directing the ingenium.One would expect Aristotelian treatises to define Logic as a science of syllogism or a science of demonstration. They do not. They present it as the ars disserendi or modus sciendi, which teaches the right way of acquiring knowledge. This is usually taken to be a “Ramist” element, but the Aristotelians do not make any mention of Ramus. The Latin expression is that of ars disserendi, the art of discourse, taken in a specific sense as “a logical chain of ideas put into discourse,” a demonstrative speech.I will comment upon one treatise on Logic in particular, that of the Collegium Conimbricense, which does not need a presentation for Cartesian studies. It is published in 1606 as In universam dialecticam Aristotelis, and is the last of the series of Aristotelian commentaries that form their course. In spite of the title, as we will see, it has the pretense of being a systematic course on Logic and not merely a course on Aristotle. It has, for instance, an interesting treatise on signs, springing from De Interpretatione, that has been edited and translated recently (The Conimbricenses 2001; do Couto, 2013). We also know the name of the author of this course, although this information does not lead us further since it is only the author of this single work: Sebastião do Couto.I will speak of the Coimbrans, in plural, because the course was very much a collective enterprise. The project was led initially by Pedro da Fonseca, author of a very appreciated Metaphysics, but also of a treatise on Logic4. The section that interests us from the Coimbra course, the preliminary questions on the status of logic and on “What is the adequate subject of Dialectics,” is nothing more than a transposition of Fonseca’s argumentation from his commentary to the Metaphysics (Chapter 3 on the third book), published in 1577.What we have in both Fonseca and the Coimbra treatise is a discussion of the status of Dialectics as a science, a discussion of the conditions that the subject of a science must satisfy, a presentation of the main opinions on what the subject of Dialectics is, an extensive article dedicated to refuting Saint Thomas’s opinion that Logic deals with beings of reason, and the presentation together with a defense of the true opinion, which is that Dialectics is the art of discourse. In his series of questions over Dialectics from his Metaphysics, Fonseca argues: that ens rationis is not the subject of Dialectics; neither is the demonstration, nor syllogism, nor what he calls the modum sciendi proprie sumptum, but a “Modum disserendi, sive sciendi late sumptu.” Fonseca relies on a distinction between disserendi and sciendi as acts of the mind: properly speaking, only disserendi is an operation of the mind, sciendi is a habit. In the scientific discourse (disserendi) the mind is active; in acquiring knowledge (scire) the mind is passive. Scire is the end of knowing, disserere is the way, modum. The purpose of Logic is then to direct the mind in its activity of disserendi in order to produce a proper discourse. The Coimbrans add a lot more references to authors and the exposition is more elaborated than that of Fonseca, but the core of the argumentation is the same. We can therefore say that we have Fonseca’s voice speaking through Sebastião do Couto.Before going into the text, let me say a word about the term “dialectics.” The Coimbrans use Dialectics and Logic indiscriminately in the course of the exposition, but they do have an argument about preferring the term dialectics. The traditional view is that Dialectics signifies “the faculty of making a probable discourse, comprising the eight books on the Topics,” while Logic is “the art of conscious demonstration, exposed in the four Analytical books” (do Couto [1606] 2013, p. 23). After an extensive investigation of the use of each term by the Greeks, the Coimbrans remark that philosophers today use the term indiscriminately to signify the entire art of discourse and not specifically as the art of either probable or certain discourse. However, the term Dialectics is to be preferred because of its proximity with the verb disserere, which signifies “to discuss in a proper order.” Their justification gives us a definition of the ars disserendi:it is not because Dialectics searches for the truth through discourse, because this is common to all the other disciplines; but because it is Dialectics that teaches in what way our mind discusses rightly and without error, that is, it searches for the unknown starting from what is known (quod ea tantum doceat, quo pacto mens nostra recte, et sine errore disserat, id est incognita ex notioribus investiget). (do Couto [1606] 2001, p. 23)The conclusion is that we should call the art of proper discourse Dialectics and reserve Logic for that part of Dialectics that deals with demonstration, that is, Aristotelian Logic. Most treatises on Logic in the early modern period are called treatises on Dialectics: the evolution of the term “dialectics” parallels the understanding of Logic as an art of discourse.Regarding the question on “What is the proper subject of dialectics,” the discussion is sometimes unnecessarily intricate even though the answer has already been given. First, we must separate the formal and the material subject (the subjectum quo and the subjectum quod, the subject of inherence and the object). The material subject is the intellect and this is dealt with in the physiological science of De anima. The subject in a formal sense is taken “pro eo in quod scientiam totam suam curam impendit,” sometimes called the absolute subject or the matter of a science. Then we divide this formal subject into adequate or total, and inadequate or partial. It can also be principal or less principal (secondary). We are looking for the total subject, an equivalent for Logic of what ens is for Metaphysics. (The adequate total subject is that which encompasses everything that the science treats, like ens is for Metaphysics, as opposed to the partial subject, e.g., the created beings in Metaphysics). The Coimbrans go through several articles: one that defines what must constitute the subject of each science, that is, what the conditions are for something to be the subject of a science; a second article confronts rival opinions on the subject of Dialectics; a third article defends the thesis that the subject of dialectics is the art of discourse; a fourth article confronts some objections to this thesis.There are several conditions for something to be the subject of a science. The Coimbrans rely on three of them that are received by most dialecticians, although they will also report extensively on nine conditions that Scotus has come up with, only to obfuscate the discussion. (1) The first condition is that the subject must be one, that it, it must have a unity of sorts. For instance, in metaphysics, ens has analogical unity, ens mobile has univocal unity in Physiology, and so forth. (2) The second condition is: that all that is treated in the science should be referred in some way back to this subject, either as properties of this subject, or as its parts, or as its principles. This seems to follow from the first condition of the unity of the subject: the topics that the science discusses must not fall out of its subject. (3) The third condition is that the science must be distinguished from other sciences through its subject. The first two conditions are necessary for there to be an order in the science. The third is necessary because philosophers often steal the subject from one another. These conditions are important because they will verify the thesis that the art of discourse is the proper subject of Dialectics. The order of proper discourse is manifestly one; there cannot be several methods, like in some books “De methodis,” as there cannot be multiple ways of directing one’s mind in attaining the single truth. The second condition is also satisfied: everything taught in Dialectics pertains to discourse: the three elements of discourse, division, definition and argumentation; the propositions and terms are part of a discourse; the categories are used in a discourse, etc. This subject also distinguishes Dialectics from all other sciences because it is only Dialectics that “is invented in order to correct the vices of reason, it is only this art that elaborates instruments in order to perfect an adequate and emended knowledge.” We are far from the probable science of Aristotelian dialectics and indeed dealing with a science of the way in which we can correct our reason and conduct it on the right path, the same one that Descartes is looking for.The thesis that Logic is the art of discourse, although omnipresent in early modern Aristotelian treatises, is something of a novelty in Aristotelianism. If we follow the references given by the Coimbra manual then we cannot trace it back further than Fonseca. It is therefore remarkable that the Coimbra Jesuits take the pain to refute all known authorities on this issue, and especially Thomas and Scotus.The Coimbrans note that there are so many opinions on the subject of Dialectics that it would be difficult to find another one. They can nevertheless be reduced to three classes: one is the terminist approach that defines Logic as a science of terms or concepts; a second one is what I call the psychological approach that defines Logic as the science of the beings of reason insofar as they are the product of intellectual acts—this is the opinion of Thomas Aquinas; the third class is the plain Aristotelian approach that sees in Logic a science of syllogism and is championed by Duns Scotus.Let me briefly go through each class. In what I call the terminist group, we find those who believe that Dialectics deals with words (de vocibus). Here there are two subgroups, those that take non-signifying words to be the subject of Dialectics (voces nude sumptas), like Alexander of Aphrodisias, or signifying words, like the nominalists do (they cite Gerhard Mathys [Gregor Matthisius], a sixteenth century logician from Cologne, and Gabriel Biel). The distinction is that between syncategorematic and non-syncategorematic terms. Still in this class, there is another opinion that goes back to Avicenna: Logic deals not with words but with concepts; generating science, going from the less known to the known, is not done by words, but by concepts. This terminist opinion is easily refuted. The nominalists mistake the form for the material; it is like saying that the material of the Architect is the exemplar or the form of the building. Words, insofar as they are real qualities in a subject, are explained in physiology, that is, in De anima; the signification of words are explained by Grammar, not by Dialectics.The second candidate for the subject of Dialectics are the beings of reason: “omne ens rationis in tota sua latitudine sub Dialecticam considerationem per se cadere.” This opinion is held by Saint Thomas and his disciples, to which we can add John of Jandun. One can defend this opinion by saying that Aristotle himself tells us that philosophy deals with being, and Dialectics is part of philosophy, hence it must study a certain type of being; and this cannot be real being but only intentional being. One can also object to it that some beings of reason arise not as a result of some operation of the intellect, but simply “by nature,” from the nature of a thing: for instance, right and left are based in the nature of things, not in the intellect. Although this particular example seems to me debatable, the Coimbrans retain it as a valid objection and moderate the opinion: it is not the being of reason “in all its extension” that makes up the subject of Dialectics, but merely those beings of reason that result from the operations of the intellect. It is Toletus who proposed this more moderate opinion and it was defended by many recentiores. One could add that it is actually in conformity with Thomas Aquinas since Aquinas believed that Logic deals with the result of the operations of the intellect. It is also a very defensible opinion since ens rationis seems to satisfy all the conditions of a subject: it is unitary, everything that is taught in Dialetics is either a being of reason or part of a being of reason, and it suffices to distinguish it among other sciences. However, the opinion is not retained (non placet) for several reasons. The more receivable reason seems to me to be the following: Dialectics does not explain the nature or the principles of the beings of reason, which makes it dissatisfy the second condition for the subject of a science. Dialectics does not explain “by its own and as its own function” how concepts are formed. It would mean making Logic a sort of psychological science, whereas what is needed are not individual concepts but the discourse itself, the chain of reasons.The third class of opinions takes the intellectual acts themselves to be the subject of Dialectics, instead of the result of these intellectual acts. Aristotle divides his Logic according to the three operations of the intellect from De anima: in the Categories he deals with the simple cognition of things; in De Interpretatione, with division and composition; in the rest of the books (the Analytics), with reasoning. Logic, in this third class of opinions, is “some sort of an instrument of science, produced by reason.” The presentation of this rival opinion, which is the lengthiest one of the three, will also give us the elements from which we can reconstruct the genesis of the view that Logic is the art of discourse. The Coimbrans attribute the opinion to Scotus, to “the Arabs,” and to Albertus Magnus.A variation of this line of thought has been produced by Avicenna “and other Arabs.” They exclude from the subject of Logic the first operation of the intellect, the simple apprehension of things; they only retain definition and demonstration. Arab Logic is a modus sciendi, an instrument of knowing scientifically insofar as it contains definitions and demonstrations, for a thing is known either through a definition or through a demonstration.Albertus Magnus, following the Arab opinion, restricted even further the domain of Dialectics to demonstration—demonstration of any kind [?], not just syllogistic demonstration. Dialectics becomes a science of reason that produces an adequate discourse about any thing. Scotus, the last step in this evolution, is even more restrictive saying that only syllogism is the subject of Dialectics because all other forms of demonstration can be reduced to a syllogism. This restrictive opinion is also maintained by all the Greek commentators, Simplicius, Ammonius, and Philoponus, who take demonstration and syllogism to be the same thing, according to the Coimbrans.At this point the Coimbrans do not argue against the opinion, but they introduce an article on the art of discourse as the proper subject of Dialectics. This leads us to think that this opinion is actually a development of the third class, an extension of Scotus’ view. The thesis is the following: the art of discourse (disserendi modus) is the proper subject of Dialectics in all its amplitude, and not insofar as one author treats it or the other (read, not the subject of Aristotle’s Dialectics). What is this disserendi modus? It is simply a discourse that that brings about something unknown from something known. It has three parts: division, definition, and argumentation. It corresponds to the ontological parts that we can know of a thing: its essence, given by a definition; its parts, given by a division; and its affections or properties, given by an argumentation or a demonstration, be it syllogistic or not.Once we have this definition of the art of discourse, it is easy to refute the opinions of the third class that take the intellectual acts to be the subject of Dialectics. The intellectual acts of division and definition do not bring about something unknown from something known, which proves that these intellectual acts do not take part in dialectics. Moreover, Aristotle did not take the three intellectual acts of De Anima to be the subject of Dialectics per se, but only as constituting part of its subject, as the instruments needed for extracting the unknown from the known. In sum, Logic should not be a science of how to form intellectual acts, but a science of how to relate these intellectual in order to form a discourse.There is another interesting development in this discussion: the purpose of Dialectics, we are told, is to correct the vices of the mind. The mind errs not only in discourse, but also in simple apprehension and in judgment, in all three of the Aristotelian intellectual acts. Dialectics cannot correct simple apprehension and judgment taken individually insofar as they are produced by the intellect, but only insofar as they are used in a discourse. Dialectics cannot correct the infirmity of the mind when it mistakes an object for something else. But in correcting the discourse, that is, the chain of reasons that relate individual simple apprehensions to one other, dialectics can supplement the defect that we may have in simple apprehension. It is only by knowing things discursively that we can actually progress in our knowledge. Discursive knowledge, they say, can supplement the defect that we do not have simultaneous knowledge, like the angels.The conclusion of the lengthy discussion is that, if we speak of Logic insofar as it is treated by Aristotle, the
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