Henrik Lagerlund

This article presents a new interpretation of Nicole Oresme’s view of powers of the soul. It argues that Oresme denies that powers are virtually present in every part of the soul and that he endorses the identification of soul and powers. This has two important consequences: (1) the sensitive soul is nothing but a heterogeneous composition of different substantial parts held together; powers are not virtually present in every part of it, but are its distinct parts. (2) Oresme’s position blurs the distinction between body and soul (with the exception of the human case). Indeed, since the powers of the soul are the actual configuration of the body, and since powers are the constitutive elements of the soul, form does not seem to be distinct from the body in any sense. This feature of his philosophy becomes more obvious in his later writings. In a way, his view entails a deflationist interpretation that seeks to reduce high-order powers (like psychological ones) to lower powers (i.e., physical ones). Starting from his famous Treatise on Configurations, in which this reductionist program is developed in a radical manner, the article aims to show that this fundamental thesis concerning the nature of powers is rooted in a long-standing philosophical conviction already developed in the commentaries on Aristotle that Oresme composed at the beginning of his career.

Henrik Lagerlund explores the topic of final causality in the High and later Middle Ages. He argues that the seventeenth-century mechanists weren’t the only ones critiquing and rejecting final causality. There were earlier figures who developed a form of mechanical materialism that eschewed final causes, most notably William of Ockham and John Buridan. Lagerlund begins with the way that Ockham and Buridan in the fourteenth century understood the mereology of the body. Bodily substances were composed of essential parts and integral parts. Essential parts were its metaphysical constituents, its matter and substantial form. Integral parts were its various extended bits. This distinction generated a metaphysical divide between material objects with extended substantial forms and simple, immaterial substances like God, angels, and the human soul. And this divide raises a number of philosophical puzzles for the entities on either side of it. Of special concern to Lagerlund is the numeric identity and unity of material substances across time. Lagerlund shows how Buridan in particular struggled to make sense of the identity and unity of material substances through time. In the end, Buridan could only say that material substances are successively identical through time; they are not totally or partially identical.

In the study on Leibniz's language of thought, the author argues that Leibniz can be interpreted as belonging to the mental language tradition developed in the Middle Ages by William Ockham. By placing Leibniz in the debate about the status of truth between Hobbes and the Cartesians, he brings out his commitment to an ideal mental language mirroring the metaphysical structure of the world. The chapter also argues that Leibniz builds his logical calculus on top of this mental language. The final part of the chapter relates Leibniz's view to that of Ockham's. Although the focus of the chapter is on Leibniz's thought, the discussion thus extends backwards in time and to other early modern authors by building connections between medieval and early modern thinkers.

Peter Adamson’s fantastic series of podcasts has by now covered almost the whole of Renaissance and African philosophy. In the meantime, the sixth volume in the series of books originating from the podcast has been published. Combining Byzantine and Italian Renaissance philosophy might look like an odd choice, but given the old idea that the Renaissance began with the fall of Constantinople in 1453, it is perhaps not entirely strange to put these two together in one volume.The problem is that the timeline is off, since the Italian Renaissance, according to Adamson, starts in the fourteenth century with Petrarch, and there was very little influence on Italian thinkers, if any, from Byzantine philosophers at that... Read More.

This paper takes as its starting point a debate in the mid-fourteenth century on the nature of successive entities and whether substances can be such entities. It brings out Albert of Saxony’s view in particular. The background to this debate was William Ockham’s focus on parts and wholes in physics and their relationship to substances. There was a strong tendency in philosophy after Ockham that this perspective would come to overshadow the Aristotelian distinction between form and matter. From that point of view the paper looks at Peter of Mantua’s interesting and original view of substance. He develops this mereological account of substance and accidents and argues that there are two distinct kinds of parts, namely essential and integral parts, but he also seems to think that each essential part is composed of integral parts. His view essentially reduces form and matter to integral parts. The only exception he allows is the human intellective soul, which is devoid of integral parts. However, he still views the intellective soul as a part of a whole human being.

After Thomas Aquinas, it became standard to divide “intentio” into first and second intentions (the distinction ultimately derives from Avicenna). Roughly, the distinction captures the intentionality of concepts like “Socrates” or “human being,” which are first intentions, versus concepts like “species” or “genus,” which are second intentions. Hervaeus Natalis (d. 1323) was the first to write an independent treatise on this distinction, and he also introduced and used the word “intentionaliter” in a new way, as well as attempts a definition of the notion of intentionality, perhaps the first such attempt. His treatise is called De secundis intentionibus (On Second Intentions), and can only be described as a treatise on the philosophy of mind and about the problem of intentionality. In this article, I will place Hervaeus in relation to the debate on mental content between Henry of Ghent and John Duns Scotus, and show how he has the resources to define a concept of “intentionality” as “the mark of the mental.”

In his logical treatises, John Mair develops a method and a set of rules for the verification of modal propositions, which is in the spirit of his predecessors Ockham and Buridan, but ultimately goes beyond them. He calls this method positio de inesse. It is also by this method that the truth conditions for divided modal propositions are set out. There is a standard interpretation of it as a form of reductionist method, and scholars have been tempted to think that it was motivated by an implicit rejection of de re modal properties shared by Mair and other sixteenth- century nominalists. After presenting the background to Mair’s writings on the semantics of modal propositions, in this paper we revisit Mair's version of the method of positio de inesse. We argue that it is based on some basic semantic rules and contend that this procedure analyzes divided modal propositions into singular de re sentences referring to possible objects. Consequently, we conclude that this method does not reflect a reductionist approach to modal discourse. We instead provide an alternative interpretation.

In his commentary on Aristotle’s Physics, John Buridan (c. 1300–1361) presents his well-known rejection of final causality. The main problem he sees with it is that it requires the cause to exist before the effect. Despite this, he retains the terminology of ends. This has led to some difficulty interpreting Buridan’s view. In this article, I argue that one should not misunderstand Buridan’s terminology and think that he still retains some use or explanatory function for final causality in nature. To make this point, I look first at Buridan’s text, but then also at three thinkers who discuss Buridan’s view in detail: Albert of Saxony (d. 1390), Paul of Venice (d. 1429), and Luis Coronel (d. 1531). They all have a very clear idea of what Buridan’s view was and understand that it entails a rejection of final causality, but they also all preserve his distinctive terminology. Paul of Venice especially discusses and criticizes Buridan’s view in detail. Besides confirming my interpretation of the rejection of final causality, this study also shows that the view was extremely influential well into the sixteenth century and attributed to Buridan throughout two centuries.

In this book, Henrik Lagerlund offers students, researchers, and advanced general readers the first complete history of what is perhaps the most famous of all philosophical problems: skepticism. As the first of its kind, the book traces the influence of philosophical skepticism from its roots in the Hellenistic schools of Phyrronism and the Middle Academy up to its impact inside and outside of philosophy today. Along the way, it covers skepticism during the Latin, Arabic, and Greek Middle Ages and during the Renaissance before moving on to cover Descartes's methodological skepticism and Pierre Bayle's super-skepticism in the seventeenth century. In the eighteenth century, it deals with Humean skepticism and the anti-skepticism of Reid and Kant, taking care to also include reflections on the connections between idealism and skepticism. The book covers similar themes in a chapter on G.E. Moore and Ludwig Wittgenstein, and then ends its historical overview with a chapter on skepticism in contemporary philosophy. In the final chapter, Lagerlund captures some of skepticism's impact outside of philosophy, highlighting its relation to issues like the replication crisis in science and knowledge resistance.

"Divided chronologically into four volumes, The Philosophy of Knowledge: A History presents the history of one of Western philosophy's greatest challenges: understanding the nature of knowledge. Each volume follows conceptions of knowledge that have been proposed, defended, replaced, and proposed anew. Knowledge in Medieval Philosophy covers the development of philosophical treatments of knowledge during the Middle Ages. It covers both Arabic and Latin philosophy, as well as a range of thinkers from the period including Avicenna, Averroes, Thomas Aquinas, John Duns Scotus, William Ockham, and John Buridan. In addition, the volume explores the growth of epistemological scepticism and the subsequent claims made by a variety of philosophers that knowledge was no longer fallible."--Bloomsbury Publishing.

In this paper, I argue that it is in the fourteenth century that the problem of the compatibility or unity of efficient and final causality emerges. William Ockham and John Buridan start to flirt with a mechanized view of nature solely explainable by efficient causality, and they hence push final causality into the human mind and use it to explain for example action, morality and the good. Their argumentation introduces the problem of how to give a unified account of the world, that is, how are nature and freedom compatible. In the paper, I set up the discussion by going through some of the problems associated with final causality in the seventeenth century and show that Ockham and Buridan's problems are similar. I then argue using a formulation from Leibniz's Monadology that the problems here traced should be seen as versions of the mind/body problem