This is the first paper in a series in which we provide critical editions of four texts written between the eleventh and the thirteenth century concerning Proposition III.5 of Menelaus' Spherics. The first paper contains introductory material on the work of Ibn ʿIrāq on spherical geometry and a critical edition of his two texts on the rectification of Proposition III.5, together with translations and historical and mathematical commentaries. The second paper contains critical editions of the texts by Naṣīr al-Dīn al-Ṭūsī and Ibn Abī Jarrāda on the same subject, again with translations and historical and mathematical commentaries.

Mainly based on the study of a hitherto neglected epigraphic document from Antinoë, the present article aims at showing that the geometer Serenus – the author of two treatises On the Section of a Cylinder and On the Section of a Cone – lived at the beginning of the 3rdcentury AD. On the ground of a renewed study of various elements taken both from the treatises and the indirect tradition, it also suggests that Serenus must be placed among a scientific tradition closely linking geometry of conics and catoptrics that can be traced back to the works of Conon of Samos and Pythion of Thasos. This hypothesis raises the problem of the nature of his alleged Platonism, which is examined in relation to Menaechmus' heterodox constructivism. Finally, the study of an element in the Arabic transmission of the treatise on Conics by Apollonius enables us to clarify some point regarding the textual tradition of the treatises On the Section of a Cylinder and On the Section of a Cone.

The article considers a brief catechistic presentation of a Galenic medical doctrine, the critical days, by the 9th century translator and thinker, Qusṭā ibn Lūqā (d. 912/3), found in a manuscript in Iran. The piece is first shown to have been derived from Galen's treatise on the critical days. Then, it is discussed section by section, in commentary form, to elucidate the medical doctrines Qusṭā propounds. Lastly, the piece is compared with an earlier attempt, by al-Kindī (d. c. 870), to describe the critical days mathematically. The various medical doctrines behind the treatise are discussed, as are the varying approaches to scientific method. The article concludes with contrasting the a priori mathematical scientific method of al-Kindī with the a posteriori empirical method of Galen/Qusṭā, and offers suggestions about the chronologies of the appearances of these doctrines and texts in Arabic. A transcription of the Arabic text is appended.

I examine the theory of conditional propositions (qaḍāyā šarṭiyya muttaṣila) and conditional syllogisms (qiyāsāt šarṭiyya) in the logical works of Alfarabi (d. 950). I contextualize Alfarabi's logical doctrines related to conditional reasoning against the backdrop of the context-theory of logic, which was developed by Aristotle's ancient commentators. I show that Alfarabi thought that conditional propositions have truth-conditions. I provide conjectural truth-conditions for conditional propositions, and conjectural validity-conditions for connective conditional syllogisms. These truth-conditions and validity-conditions are shown to be sensitive to the pragmatic conditions in which conditional propositions and arguments are deployed. I end by suggesting that Alfarabi's logical pragmatism is a consequence of his adoption of the late antique context-theory of logic rather than a result of his developing Aristotle's formal syllogistic theory adumbrated in the Prior Analytics.

As is well known, taṣawwur and taṣdīq, conceptualization and assent, are essential notions in the epistemology of Arabo-Islamic philosophy. Conceptualization amounts to the definition of an object of knowledge, and assent to the recognition, via some kind of reasoning, that this definition is true. One of the authors who dealt with both topics in greatest depth was al-Fārābī, whose oeuvre exerted a profound influence on Ibn Bājja. This article analyzes the materials on taṣawwur and taṣdīq found in Ibn Bājja's notes regarding al-Fārābī's writings on logic and scientific method, namely the glosses to Kitāb al-Burhān. The analysis shows, on the one hand, that he understood perfectly the importance of both terms in al-Fārābī's construal of Aristotle's scientific method; and on the other, that he used them to deal with human thought processes. Indeed, conceptualization and assent were essential notions for Ibn Bājja, and underlie some of his best-known works.

The article aims to demonstrate that Avicenna's (d. 428/1037) centrality in Islamic intellectual history is not restricted to the branches of theoretical philosophy; rather, he also has had a deep and strong influence on the conception of practical philosophy until modern times. I will discuss the impact of Avicenna's view of practical philosophy by analyzing his different classifications of practical philosophy throughout his career and the factors behind his disregard for practical philosophy in his philosophical summas on the basis of his view of the relationship between philosophy and šarīʿa. To demonstrate my argument regarding Avicenna's influence on the conception of practical philosophy in Islamic tradition, I will refer to major works on the classification of sciences, and the commentaries (šurūḥ) and glosses (ḥāwāšī) on the two most important and widely circulated philosophical summas in the post-Avicennan philosophy, which are al-Abharī's (d. 663/1264) Hidāyat al-ḥikma and al-Kātibī's (d. 675/1276) Ḥikmat al-ʿayn.

Aristotle did not develop the quantification of the predicate, but, as shown in a recent paper by Hasnawi, Ibn Sīnā did. In fact, assuming the Aristotelian subject-predicate structure, Ibn Sīnā qualifies those propositions that carry a quantified predicate as deviating (muḥarrafa) propositions. A consequence of Ibn Sīnā’s approach is that the second quantification is absorbed by the predicate term. The clear differentiation between a quantified subject, that settles the domain of quantification, and a predicative part, that builds a proposition over this domain, corresponds structurally to the distinction, made in constructive type theory, between the type of sets and the type of propositions.

Neither did Aristotle combine his logical analysis of quantification with his ontological theory of relations or equality. But Ibn Sīnā makes use of syllogisms that require a logic of equality, and considered cases where quantification combines via equality with singular terms. Moreover these reflections provide the basis for his theory of numbers that is based on the interplay between the One and the Many. If we combine Ibn Sīnā’s metaphysical theory of equality with his work on the quantification of the predicate, a logic of equality comes out naturally. Indeed, the interaction between quantification of the predicate and equality can be applied to Ibn Sīnā’s own examples of syllogisms involving these notions. By using the formal instruments provided Martin-Löf's constructive type theory, the present paper establishes links between Ibn Sīnā’s metaphysics and his logical work: links that have been discussed in relation to other topics by Thom and Street. Ibn Sīnā did not develop a logic of identity, but he did develop the conceptual means to do so.

Avicenna came to an unexpected conclusion in the treatise On Plants in al-Šifāʾ: that plants are not alive. This judgment is surprising in view of Aristotle's opinion that that which has a soul is alive. This paper shows that there is a development in Avicenna's thought on plants' life. He begins with the Aristotelian view that plants are alive inasmuch as they possess a soul, as we see in his early A Compendium on the Soul. Later, however, through his investigation of the faculties of the soul, discussed mainly in the first part of the Canon of Medicine, he is led to conclude that plants could not be said to be alive. This paper indicates the importance of considering the influence of Avicenna's medical findings on his philosophical arguments when examining the development of his thought.

Since the beginning of mankind, man has been concerned with the conservation of food in order to prolong its edibility. Over time, different food preservation methods have been discovered and improved, and there are many works that describe these techniques. This work will describe the knowledge and the development of preservation techniques of inhabitants of the Iberian Peninsula. The work focuses on the various achievements from the first to the sixteenth centuries, allowing us to appreciate the different historic contributions. The selected and consulted works are: L.J.M. Columela, Los doce libros de Agricultura (The Twelve Books of Agriculture), Abū al-Jayr, Kitāb al-Filāḥa. Tratado de agricultura (Book of Agriculture), Ibn Baṣṣāl, Kitāb al-Filāḥa. Libro de agricultura (Book of Agriculture), Ibn al-ʿAwwām, Kitāb al-Filāḥa. Libro de Agricultura (Book of Agriculture), Ibn Luyūn, Kitāb al-Filāḥa. Tratado de Agricultura (Book of Agriculture), Alonso de Herrera, Agricultura general (General Agriculture).

The aim of this article is to present a medieval Arabic report regarding six animals from the Gulf of Aden, to provide a zoological identification of five of the animals in question, which may be identified, and to comment on the biological data provided by the report in the light of both contemporary and modern zoological knowledge and, thus, to evaluate the scientific standard of the report.