The science of logic

Logic concerns the norms enabling a person to distinguish between right and wrong, both in definitions that give information about the essence of things, and in arguments that assure apperception.

This comes about as follows: The basis of perception is the sensibilia that are perceived by the five senses. All living beings, those which are rational as well as the others, participate in this kind of perception. Man is distinguished from the animals by his ability to perceive universals, which are things abstracted from the sensibilia.

Man is enabled to do this by virtue of the fact that his imagination obtains, from individual objects perceived by the senses and which agree with each other, a picture conforming to all these individual objects. Such (a picture) is a universal.

The mind then compares the individual objects that agree with each other, with other objects that (also) agree with them in some respects. It thus obtains a picture conforming to both of the two groups of objects compared), .in as much as they agree with each other. In this way, abstraction continues to progress.

Eventually, it reaches the universal (concept), which admits no other universal (concept) that would, agree with it, and is, therefore, simple.

For instance, from the individual specimens of man, the picture of the species to which all the individual specimens conform is abstracted. Then, man (the human species) is compared with the animals, and the picture of the genus to which both men and animals conform is abstracted.

Then, this is compared with the plants, until, eventually, the highest genus is reached, which is “substance.”

There is no (other) universal (concept) that would in any way agree with it. Therefore, the intellect stops here and makes no further abstraction.

God created in man the ability to think. Through it, he perceives the sciences and crafts. Knowledge is either a perception (tasawwur) of the essence of things - tasawwur meaning a primitive kind of perception not accompanied by (the exercise of) judgment - or it is apperception (tasdiq), that is, the judgment that a thing is so.

(Man’s) ability to think may try to obtain the desired (information) by combining the universals with each other, with the result that the mind obtains a universal picture that conforms to details outside. Such a picture in the mind assures a knowledge of the quiddity of the individual objects. Or, (man’s) ability to think may judge one thing by another and draw conclusions (from the one thing as to the other).

Thus, (the other thing) is established in (the mind). This is apperception. In fact, (apperception) ultimately reverts to perception, because the only use of having (perception) is (to achieve) knowledge of the realities of things, which is the re- quired goal of apperceptive 689 knowledge.

(Man’s) ability to think may embark on this (process) in either the right or the wrong way. Selection of the way to be followed by man’s ability to think in its effort to attain the knowledge desired, requires discernment, so that (man) can distinguish between right and wrong. This (process) became the canon of logic.

When the ancients first began to discuss (logic), they did so in a sententious, disconnected manner by selecting certain stray propositions. Logical methods were unimproved. The problems of logic were not seen together. Eventually, Aristotle appeared among the Greeks. He improved the methods of logic and systematized its problems and details. He assigned to logic its proper place as the first philosophical discipline and the introduction to philosophy. Therefore, Aristotle is called “the First Teacher.” 690

His work on logic is called “the Text” made up of 8 books.

• 3 are on analogical reasoning
• 5 are on the matter (to which analogical reasoning is applied).

This is because the objects of apperception are of different kinds. Some of them concern things that are certain by nature. Others concern things that are hypothetical in various degrees. Therefore, logic studies analogical reasoning from the point of view of the desired (information) it is expected to yield. It studies what the premises (of the desired information) ought to be, as seen in this light, and to which kind of certain or hypothetical knowledge the (desired information) belongs.

Logic studies analogical reasoning (the syllogism), not with some particular object in mind but exclusively with regard to the way in which it is produced. Therefore, the first study, it is said, is undertaken with regard to matter, that is, the matter that produces some particular certain or hypothetical information. The second study, it is said, is undertaken with regard to the form and the manner in which analogical reasoning (the syllogism) in general is produced. Thus, the number of the books on logic came to be eight.

Book 1 deals with the highest genera that abstraction among the sensibilia may attain in the mind and that admit no (more universal) genera above them. It is called Kitab al-Maqulat (Categories).

Book 2 deals with the various kinds of apperceptive propositions. It is called Kitab al-‘Ibarah (Hermeneutics).

Book 3 deals with analogical reasoning (the syllogism) and the form in which it is produced in general. It is called Kitab al-Qiyas (Analytics). Here ends the logical study from the point of view of (its) form.

Book 4 is the Kitab al-Burhan (Apodeictica). It studies the kind of analogical reasoning (the syllogism) that produces certain (knowledge). It also studies (the problem of) why its premises must be certain ones. In particular, it mentions other conditions for yielding certain knowledge. For instance, the (premises) must be essential, primary, and so on.

This book contains a discussion of determinatives 692 and definitions, because one wants them to be certain, since it is necessary - nothing else is possible - that a definition conform to the thing defined.

Therefore, (definitions) were treated by the ancients in this book.

Book 5 is the Kitab al-Jadl (Topics). Jadl (“disputation”) is the kind of analogical reasoning that shows how to cut off a troublesome adversary and silence one’s opponent, and teaches the famous (methods) to be employed to this end. It is also concerned with other conditions required in this connection. They are mentioned here. The book deals with the “places” (topoi) from which the syllogism is evolved by using them to clarify the so-called middle term that brings the two ends of the desired information together . 693 It also deals with the conversion of terms.

Book 6 is the Kitab as-Safsatah (Sophistici Elenchi). Sophistry is the kind of analogical reasoning that teaches the opposite of the truth and enables a disputant to confuse his opponent. The (book) is bad because of its purpose. It was written only so that one might know sophistical reasoning and be on guard against it.

Book 7 is the Kitab al-Khitabah (Rhetoric). Rhetoric is the kind of analogical reasoning that teaches how to influence the great mass and get them to dowhat one wants them to do. It also teaches the forms of speech to be employed in this connection.

Book 8 is the Kitdb ash-Shi’r (Poetics). Poetics is the kind of analogical reasoning that teaches the invention of parables and similes, especially for the purpose of (encouraging oneself and others) to undertake something or avoid doing something. It also teaches the imaginary propositions 694 to be employed in this connection.

These are the eight books on logic according to the ancients. After logic had been improved and systematized, the Greek philosophers were of the opinion that it was necessary to discuss the five universals providing the perception that 695 conforms to the quiddities outside or to their parts or accidents. The (five) are genus, difference, species, property, and general accident. 696

Therefore, they took the subject up in a special book concerned with the (five universals), which serves as an introduction to the discipline. Thus, the books on (logic) came to be nine. All of them were translated in Islam. The Muslim philosophers wrote commentaries and abridgments of them. Al-Farabi and Avicenna, for instance, did this, and, later on, the Spanish philosopher, Averroes. Avicenna wrote the Kitab ash-Shifa’,697 which comprises all the seven philosophical disciplines. Later on, more recent scholars have changed the terminology of logic.

They added to the study of the five universals the (study of) its fruit, namely, the discussion of definitions and descriptions which they took over from the Apodeictica. They discarded the Categories, because (the logicians’) study of the book is accidental and not essential. To the Hermeneutics they added the discussion of the conversion (of terms), whereas the ancient books included that subject in the Topics, 698 but, in some respects, it does fall under the discussion of propositions.

Then, they discussed analogical reasoning in as much as it produces the desired information in general, and without regard to any matter. They discarded study of the matter to which analogical reasoning (is applied). That concerned five books, the Apodeictica, the Topics, the Rhetoric, the Poetics, and the Sophistici Elenchi.

Some of them occasionally touched a little on those books. (But in general,) they neglected them, as if they had never been, whereas they are a very important basis of the discipline.

Then, they thoroughly discussed their writings on logic and studied them as a discipline in its own right, not as an instrument for the sciences. This resulted in a long and extensive discussion of the subject. The first to do this was the imam Fakhr-ad-din b. al-Khatib. 699 He was followed by Afdal-ad-din al-Khunaji.

Al-Khunaji’s books are used by contemporary easterners as reference works. On logic, he wrote the long Kitab Kashf al-asrar, the Mukhtasar al-mujiz which is good as a textbook, and the Mukhtasar al jumal.

The last-mentioned work consists of four leaves and gives a synopsis of the discipline and its basic principles. Contemporary students use it and profit from it.

The books and methods of the ancients are avoided, as if they had never been, although they are full of the results and useful aspects of logic, as we have stated.

The early Muslims and the early speculative theologians greatly disapproved of the study of logic. They vehemently attacked it. They forbade the study and teaching of it. Later on, ever since al-Ghazzali and the imam Ibn al-Khatib, scholars have been somewhat more lenient in this respect. Since that time, they have gone on studying(logic), except for a few who have recourse to the opinion of the ancients concerning it and shun it and vehemently disapprove of it.