Unheard of Objects of Knowledge: A Controversial Principle of Buridan's Epistemic Logic

UNHEARD OF OBJECTS OF KNOWLEDGE: A CONTROVERSIAL PRINCIPLE OF BURIDAN'S EPISTEMIC LOGIC INTRODUCTION A major topic of controversy among fourteenth-century philosophers was that of the objects of knowledge—whether such objects are propositions, things designated by the terms of propositions, or entities of some other sort.1 Indeed, for example, this topic was the subject-matter of one of the clauses of the 1340 statute of the Faculty of Arts at the University of Paris. The Faculty seems to have been concerned to protect itself against, among other things, the incursion of one of the then recognized doctrines on the objects of knowledge—the doctrine that "there is no knowledge of things which are not signs, that is, which are not terms or statements."2 The statute was signed by the newly-appointed Rector of the University, Jean Buridan. On the topic of the objects of knowledge Buridan himself took a position consistent with the pertinent clause of the 1340 statute. One important and interesting section of text that bears on the topic is to be found in Buridan's treatment of the thirteenth sophism of appellation in Sophismata? My own interest in the fourteenth-century controversy concerning die objects of knowledge was sparked by E. A.Moody's 11A Quodlibetal Question of Robert Holkot, O.P. On the Problem of the Objects of Knowledge and of Belief," Speculum 39 (1964): 53-74, and T. K.Scott's "John Buridan on die Objects of Demonstrative Science," Speculum 40 (1965): 654-73. These papers discuss various aspects of die controversy, and are very useful as an introduction to at least some of the principal participants and their respective positions. Denifle-Chatelain, ed. Chartularium Universitatis Parisiensis, Vol. II No. 1042 (Paris, 1891), in E.A.Moody, "Ockham, Buridan, Nicholas of Autrecourt," in James F. Ross, ed. Inquiries into Medieval Philosophy (Connecticut: Greenwood, 1971), 289: "...scientiam nullam esse de rebus non sunt signa, id est, que non sunt termini vel orationes...." 3English translations oí Sophismata follow Sophisms on Meaning and Truth, a translation widi introduction by T.KScott (New York: Appleton-Century-Crofts, 1966). But I have also made use of a copy of an edition of Sophismata published by Antoine Denidel and Nicolas de la Barre in Paris, 1496-1500, and a copy of Fabienne Pironet's, Iohanni Buridani Summularum Tractatus nonus: De practica sophismatum (Sophismata), Critical Edition and Introduction (Nijmegen: Ingenium, 1997). On die advice of an anonymous referee, I have taken Pironet's work to be "definitive"; and, consequently, ail Latin quotations from Sophismata appearing in footnotes are drawn from her edition. I should add, however, that I 203 Franciscan Studies, 57 (1999) 204Anthony Willing In what follows, I examine Buridan's position as it emerges in that section. BURIDAN ON ARISTOTLE'S TREATMENT OF AN EPISTEMIC PARADOX In anticipation of the presentation of his thirteenth sophism of appellation, Buridan reminds us of an epistemic paradox posed by Aristotle.4 Suppose that an individual, s, knows that every triangle has three angles equal to two right angles; but suppose, too, that s has never heard of isosceles triangles. Then an unsophisticated reasoner might be led to contradiction in the following way: (1)s knows that every triangle has three angles equal to two right angles. (2)Every isosceles is a triangle. Therefore (3)s knows that every isosceles has three angles equal to two right angles. But (4)s does not know that there are isosceles triangles. Therefore (5)s does not know that every isosceles has three angles equal to two right angles. Therefore (6)s both knows and does not know that every isosceles has three angles equal to two right angles. Such paradoxes have been discussed extensively in recent times. It is to Aristotle's credit that, once again, he perceives what is destined to become a long-lived philosophical problem, and goes on have detected no substantial difference, on the matters widi which I am concerned, between die above-mentioned editions. ^Posterior Analytics I, 1. 71al9-30; I, 24. 86a22-9. See also Prior Analytics II, 21. 67a8-67bl2. Unheard of Objects of Knowledge205 to propose his own solution. Not surprisingly, Aristotle's solution...