In this paper I examine Avicenna’s conception of the consequence relation. I will consider in particular his categorical and hypothetical logics. I will first analyse his definition of the implication and will show that this relation is not a consequence relation in his frame. Unlike the medieval logicians, he does not distinguish explicitly between material and formal consequences. The arguments discussed in al-Qiyās, where the conclusion is true only in some matters, and would seem close to a material consequence for (...) that reason, are rejected explicitly as not syllogistic. He also rejects the ‘enthymemes’ unless they are complemented by their missing premise and the superfluous premises which, according to him, should promptly be ruled out. It seems then that the consequence relation in his theory is formal. It can be characterized as being ‘productivity in all matters’ or ‘necessary truth preserving’. It is illustrated by some single premise arguments, and above all by all kinds of syllogisms which, in his theory, are more numerous and various than in Aristotle’s one. The syllogism may contain two or more premises, including disjunctive ones. When it is hypothetical, it may lead to several conclusions. The premises may be in conflict, but then, the conclusion is false. He thus rejects the principle according to which ‘anything follows from a contradiction’. But, unlike what some scholars say, he does not admit any connexive principle. In the compound syllogisms, the conclusion follows by steps, each step taking two premises at once. (shrink)

The purpose of this paper is to present a very versatile family of logical systems ofpositionalortopologicallogic. These systems—obtained by generalizing the existing systems of chronological logic—are to have a very general nature, capable of reflecting the characteristics of a wide range of logical systems, including not only chronological (alsotemporalortense) logic, but also what we may call locative or place logic, and even a logic of “possible worlds”.

The beginning of the 20th century has witnessed a significant development that has renewed and stimulated the long passionate historical relationship between two great civilisations which are traditionally known as the West and the East. Following their ancestors who cultivated the quest for knowledge tradition, some Arab scholars have come to leading European countries to learn the latest advancement in knowledge. They did not expect they would be confronted with what seems to be the poor showing of their scientific and (...) cultural heritage according to the assessment that was carried out in the previous century by Western scholars and historians. The Western study of the Eastern heritage had such influence that it has generated new Arab intellectual elite which blames the past for the present difficulties. Following the discovery of major scientific Arabic works in the second half of the 20th century, some Arab scholars like Ibrahim Madkour realised that they had in fact just misunderstood their own tradition. What is the source of their misunderstanding? How did they become aware of it? And how can a better understanding of the past change present attitudes and guide future actions? By attempting to provide some answers to such questions, the aim of this paper is to shed light on what seems to be a turning point in modern Arabic intellectual history. (shrink)