Jon McGinnis

The paper treats Avicenna’s ’metaphysical’ argument for the existence of God and the modal metaphysics that underpins it. Earlier analyses of modalities attempted to reduce necessity, possibility and impossibility to nonmodal elements, which was done most commonly by appealing to a temporal frequency model of modalities. In contrast, Avicenna believed that modalities were an inherent feature of existence, and so just as there is nothing more basic than existence, so likewise there is nothing more basic in term of which modalities can be explained. The article concludes by considering how Avicenna’s modal metaphysics in turn provides him the means to show the absolute and nonconditional necessity of God, as opposed to the conditional necessity of earlier ’physical’ arguments

Avicenna's discussion of space is found in his comments on Aristotle's account of place. Aristotle identified four candidates for place: a body's matter, form, the occupied space, or the limits of the containing body, and opted for the last. Neoplatonic commentators argued contra Aristotle that a thing's place is the space it occupied. Space for these Neoplatonists is something possessing dimensions and distinct from any body that occupies it, even if never devoid of body. Avicenna argues that this Neoplatonic notion of space is untenable on the basis of three arguments. In general he maintains that bodies' impenetrability is explained by reference to dimensionality. Consequently, if it is dimensionality that explains impenetrability, and yet as the Neoplatonists hold space inherently possesses dimensions, material bodies could never interpenetrate space and so occupy it and thus bodies could never have a place. The conclusion is patently false. In additions Avicenna argues that the method used to arrive at the possibility of space is illicit, and so Neoplatonist cannot show that space is even possible. Thus, concludes Avicenna, Aristotle's initial account must be correct. The paper outlines the historical context of this debate and then treats Avicenna's arguments against space in detail.

Avicenna’s _Physics_ is the very first volume that he wrote when he began his monumental encyclopedia of science and philosophy, _The_ _Healing_. Avicenna’s reasons for beginning with _Physics_ are numerous: it offers up the principles needed to understand such special natural sciences as psychology; it sets up many of the problems that take center stage in his _Metaphysics_; and it provides concrete examples of many of the abstract analytical tools that he would develop later in _Logic_. While Avicenna’s _Physics _roughly follows the thought of Aristotle’s _Physics_, with its emphasis on natural causes, the nature of motion, and the conditions necessary for motion, the work is hardly derivative. It represents arguably the most brilliant mind of late antiquity grappling with and rethinking the entire tradition of natural philosophy inherited from the Greeks as well as the physical thought of Muslim speculative theologians. As such, _Physics_ is essential reading for anyone interested in understanding Avicenna’s complete philosophical system, the history of science, or the history of ideas.

Il naturale senso della logica in relazione alla scienza è quello di fornire un linguaggio alle acquisizioni epistemologiche: tale sembra essere il senso assegnatogli anche da Avicenna in al-Mantiq. La questione in realtà è molto più profonda: quale relazione c'è fra gli universali predicabili e gli oggetti della scienza? Attraverso l'esame della questione quale è delineata nel Madkhal, in particolare in merito al genere e alla differenza, e il loro ruolo nelle scienze in alcuni passaggi del Kitab al-Burhan, l'A. verifica l'applicazione delle considerazioni teoretiche in un problema fisico pratico affrontato nel Kitab-al-Tabi'iyat

The forma fluens/fluxus formae debate concerns the question as to whether motion is something distinct from the body in motion, the flow of a distinct form identified with motion , or nothing more than the successive states of the body in motion, the flow of some form found in one of Aristotle's ten categories . Although Albertus Magnus introduced this debate to the Latin West he drew his inspiration from Avicenna. This study argues that Albertus misclassified Avicenna's position, since Albertus could not conceptualize motion at an instant, whereas it is claimed here this was the very position Avicenna adopted. The paper includes an overview of Albertus's discussion and a brief survey of the Avicennan sources upon which Albertus drew. The heart of the paper treats Avicenna's analysis of motion at an instant. Avicenna's general argument was that since spatial points have no extremities, nothing in principle prevents a moving object from being at a spatial point for more than an instant, understood as a limit. It is then argued that Avicenna had the philosophical machinery to make sense of a limit, albeit not in mathematical terms, but in terms of an Aristotelian potential infinite

Aristotle's account of place in terms of an innermost limit of a containing body was to generate serious discussion and controvery among Aristotle's later commentators, especially when it was applied to the cosmos as a whole. The problem was that since there is nothing outside of the cosmos that could contain it, the cosmos apparently could not have a place according to Aristotle's definition; however, if the cosmos does not have a place, then it is not clear that it could move, but it was thought to move, namely, in its daily revolution, which was viewed as a kind of natural locomotion and so required the cosmos to have a place. The study briefly outlines Aristotle's account of place and then considers its fate, particularly with respect to the cosmos and its motion, at the hands of later commentators. To this end, it begins with Theophrastus' puzzles concerning Aristotle's account of place, and how later Greek commentators, such as Alexander of Aphrodisias, Themistius and others, attempted to address these problems in what can only be described as ad hoc ways. It then considers Philoponus' exploitation of these problems as a means to replace Aristotle's account of place with his own account of place understood in terms of extension. The study concludes with the Arabic Neoplatonizing Aristotelian Avicenna and his novel introduction of a new category of motion, namely, motion in the category of position. Briefly, Avicenna denies that the cosmos has a place, and so claims that it moves not with respect to place, but with respect to position