Roger Bacon

The estimative power has been widely discussed in modern scholarly literature. This chapter complements the existing picture by analysing medieval Latin views concerning its role as the explanans of the social behaviour of humans and other animals. Although medieval authors rarely focus on this function, the chapter shows that the estimative power plays an important explanatory role both in philosophical psychology and political philosophy.

[Sensation, Causality, and Attention: Roger Bacon and Peter Olivi] This paper investigates what conditions are to be met for sensory perception to occur. It introduces two diff erent theories of perception that were held by two medieval Franciscan thinkers — namely, Roger Bacon (1214/1220–1292) and Peter Olivi (ca. 1248–1298). Bacon analyses especially the causal relation between the object and the sensory organ in his doctrine of the multiplication of species. In his view, a necessary condition of perception is the reception (...) of the species in a fully disposed sensory organ. On the contrary, Olivi stresses the active role of the sensory power. A necessary condition of sensation is the aspectus — i.e. the focus of our power’s attention on the object. Furthermore, the paper investigates whether and how each of the two thinkers can deal with the arguments proposed by his opponent — namely whether Bacon’s theory is able to explain attention and what the causal role of the object in Olivi’s theory is. (shrink)

In his article, “The Logic of Liberty” (Journal of Ayn Rand Studies 12, no. 1), Roger Bissell uses an analytical diagram to show that Ayn Rand was wrong to characterize the differences between liberals and conservatives in terms of the mind-body dichotomy. Bissell claims that the key philosophical difference is not the mind-body dichotomy, but the malevolent universe premise. However, the diagram Bissell uses to discredit Rand’s position exhibits a serious design flaw: it presumes the mind-body split by implying the (...) metaphysical superiority of one over the other. This fundamental flaw in his analysis renders his criticism of Rand invalid. (shrink)

This paper tries to understand how three medieval philosophers (Roger Bacon, Albert the Great and John Buridan) developed the idea of a special logic for ethics, taking into account Aristotle's thesis according to which ethics does not need theoretical syllogisms and uses a special kind of scientific reasoning. If rhetoric is a good candidate, we find three different readings of this approach and then three different theories of ethical reasoning.

El artículo examina tres propuestas de explicación del fenómeno de refracción de la luz formuladas por los pensadores medievales Roger Bacon, John Pecham y Erazmus Ciolek Witelo. Se muestra, en el caso de Bacon, que la explicación estaba soportada en una metafísica de la propagación de los poderes causales y anidaba un conflicto insalvable. En el caso de Pecham se muestra un mayor compromiso con la necesidad de una ley cuantitativa que, desafortunadamente, conduce a una explicación frustrada. Finalmente, se valora (...) el deseo de Witelo por introducir elementos cosmológicos en su explicación. (shrink)

Il ne va pas de soi que l’alchimie, science du perfectionnement des métaux, se soit intéressée à la prolongation de la vie. C’est en fait à la faveur des ambiguïtés lexicales et conceptuelles liées aux termes désignant les substances chimiques que s’est effectué dans l’alchimie arabe un rapprochement entre la perfection des métaux et la guérison des êtres vivants. La doctrine de la quintessence de Rupescissa, puis les théories de Paracelse achèveront cette évolution qui donne à l’alchimie sa double dimension, (...) chimique et médicale, rationnelle et mythique. (shrink)

In this paper I challenge the claim that Bacon considered the operation of species as limited to the physical and sensory levels and demonstrate that in his view, the very same species issued by physical objects operate within the intellect as well. I argue that in Bacon the concept of illumination plays a secondary role in the acquisition of knowledge, and that he regarded innate knowledge as dispositional and confused. What was left as the main channel through which knowledge is (...) gained were species received through the senses. I argue that according to Bacon these species, representing their agents in essence, definition and operation, arrive in the intellect without undergoing a complete abstraction from matter and while still retaining the character of agents acting naturally. In this way Bacon sets the intellect as separate from the natural world not in any essential way, but rather as it were in degree, thus supplying a theoretical justification for the ability to access and know nature. (shrink)

This essay deals with the contrary opinions of Thomas Aquinas and Meister Eckhart on synderesis and conscience. In his theory, Thomas Aquinas focuses more on prudence and less on conscience. Meister Eckhart is the proponent of an attitude ethics focusing on the notion of scintilla animae. For Thomas Aquinas, the Aristotelian thinker, the practical syllogism links judgement to spiritual values, whereas Meister Eckhart gives priority to self-predication. By means of self-predication, action and normativity can be combined immediately; the practical syllogism (...) combines them in an indirect way. (shrink)

With the introduction of Greco-Islamic science and natural philosophy, medieval natural philosophers were confronted with three distinct astronomical systems: Aristotelian, Ptolemaic, and the system of al-Bitruji. A fundamental problem that each had to confront was how to explain simultaneous contrary motions in the heavens -for example, the sun's motion, which moves east to west with a daily motion while simultaneously moving west to east along the ecliptic- within an Aristotelian physical system that assumed that a simple body could have only (...) one proper motion. How medieval natural philosophers resolved this problem is the focus of the article. (shrink)

In his rich and detailed study, Baldwin explains how this image of a seated man and a dancing woman embodies themes and motifs that can be found in the work of nineteenth-century artists from Eugéne Delacroix to John Frederick Lewis to ...