Avicenna (ABN ALI AL HOSAIN IBN ABDALLAH IBN SINA, called by the Latins AVICENNA), Arabian physician and philosopher, b. at Kharmaithen, in the province of Bokhara, 980; d. at Hamadan, in Northern Persia, 1037. From an autobiographical sketch which has come down to us we learn that he was a very precocious youth; at the age of ten he knew the Koran by heart; before he was sixteen he had mastered what was to be learned of physics, mathematics, logic, and metaphysics; at the age of sixteen he began the study and practice of medicine; and before he had completed his twenty-first year he wrote his famous “Canon” of medical science, which for several centuries, after his time, remained the principal authority in medical schools both in Europe and in Asia. He served successively several Persian potentates as physician and adviser, travelling with them from place to place, and despite the habits of conviviality for which he was well known, devoted much time to literary labors, as is testified by the hundred volumes which he wrote. Our authority for the foregoing facts is the “Life of Avicenna,” based on his autobiography, written by his disciple Jorjani (Sorsanus), and published in the early Latin editions of his works. Besides the medical “Canon,” he wrote voluminous commentaries on Aristotle‘s works and two great encyclopedias entitled “Al Schefa”, or “Al Chifa” (i.e. healing) and “Al Nadja” (i.e. deliverance). The “Canon” and portions of the encyclopedias were translated into Latin as early as the twelfth century, by Gerard of Cremona, Dominicus Gundissalinus, and John Avendeath; they were published at Venice, 1493-95. The complete Arabic texts are said to be in MS. in the Bodleian Library. An Arabic text of the “Canon” and the “Nadja” was published in Rome, 1593. Avicenna’s philosophy, like that of his predecessors among the Arabians, is Aristoteleanism mingled with Neo-Platonism, an exposition of Aristotle‘s teaching in the light of the Commentaries of Themistius, Sirnplicius, and other neo-Platonists. His Logic is divided into nine parts, of which the first is an introduction after the manner of Porphyry’s “Isagoge”; then follow the six parts corresponding to the six treatises composing the “Organon”; the eighth and ninth parts consist respectively of treatises on rhetoric and poetry. Avicenna devoted special attention to definition, the logic of representation, as he styles it, and also to the classification of sciences. Philosophy, he says, which is the general name for scientific knowledge, includes speculative and practical philosophy. Speculative philosophy is divided into the inferior science (physics), and middle science (mathematics), and the superior science (metaphysics including theology). Practical philosophy is divided into ethics (which considers man as an individual); economics (which considers man as a member of domestic society); and politics (which considers man as a member of civil society). These divisions are important on account of their influence on the arrangement of sciences in the schools where the philosophy of Avicenna preceded the introduction of Aristotle‘s works. A favorite principle of Avicenna, which is quoted not only by Averroes but also by the Schoolmen, and especially by Albert the Great, was intellectus in formis agit universalitatem, that is, the universality of our ideas is the result of the activity of the mind itself. The principle, however, is to be understood in the realistic, not, in the nominalistic sense. Avicenna’s meaning is that, while there are differences and resemblances among things independently of the mind, the formal constitution of things in the category of individuality, generic universality, specific universality, and so forth, is the work of the mind. Avicenna’s physical doctrines show him in the light of a faithful follower of Aristotle, who has nothing of his own to add to the teaching of his master. Similarly, in psychology, he reproduces Aristotle‘s doctrines, borrowing occasionally an explanation, or an illustration, from Alfarabi. On one point, however, he is at pains to set the true meaning, as he understands it, of Aristotle, above all the exposition and elaboration of the Commentators. That point is the question of the Active and Passive Intellect. (See Arabian School of Philosophy) He teaches that the latter is the individual mind in the state of potency with regard to knowledge, and that the former is the impersonal mind in the state of actual and perennial thought. In order that the mind acquire ideas, the Passive Intellect must come into contact with the Active Intellect. Avicenna, however, insists most emphatically that a contact of that kind does not interfere with the independent substantiality of the Passive Intellect, and does not imply that it is merged with the Active Intellect. He explicitly maintains that the individual mind retains its individuality and that, because it is spiritual and immaterial, it is endowed with personal immortality. At the same time, he is enough of a mystic to maintain that certain choice souls are capable of arriving at a very special kind of union with the Universal, Active, Intellect, and of attaining thereby the gift of prophecy. Metaphysics he defines as the science of supernatural (ultra-physical) being and of God. It is, as Aristotle says, the theological science. It treats of the existence of God, which is proved from the necessity of a First Cause; it treats of the Providence of God, which, as all the Arabians taught, is restricted to the universal laws of nature, the Divine Agency being too exalted to deal with singular and contingent events; it treats of the hierarchy of mediators between God and material things, all of which emanated from God, the Source of all sources, and Principle of all principles. The first emanation from God is the world of ideas. This is made up of pure forms, free from change, composition, or imperfection; it is akin to the Intelligible world of Plato, and is, in fact, a Platonic concept. Next to the world of ideas is the world of souls, made up of forms which are, indeed, intelligible, but not entirely separated from matter. It is these souls that animate and energize the heavenly spheres. Next to the world of souls is the world of physical forces, which are more or less completely embedded in terrestrial matter and obey its laws; they are, however, to some extent amenable to the power of intelligence in so far as they may be influenced by magic art. Lastly comes the world of corporeal matter; this, according to the Neo-Platonic conception which dominates Avicenna’s thought in this theory of emanation, is of itself wholly inert, not capable of acting but merely of being acted upon (Occasionalism). In this hierarchical arrangement of beings, the Active Intellect, which, as was pointed out above, plays a necessary role in the genesis of human knowledge, belongs to the world of Ideas, and is of the same nature as the spirits which animate the heavenly spheres. From all this it is apparent that Avicenna is no exception to the general description of the Arabian Aristoteleans as neo-Platonic interpreters of Aristotle. There remain two other doctrines of a general metaphysical nature which exhibit him in the character of an original, or rather an Arabian, and not a neo-Platonic, interpreter. The first is his division of being into three classes: (a) what is merely possible, including all sublunary things; (b) what is itself merely possible but endowed by the First Cause with necessity; such are the ideas that rule the heavenly spheres; (c) what is of its own nature necessary, namely, the First Cause. This classification is mentioned and refuted by Averroes. The second doctrine, to which also Averroes alludes, is a fairly outspoken system of pantheism, which Avicenna is said to have elaborated in a work, now lost, entitled “Philosophia Orientalis”. The Scholastics, apparently, know nothing of the special work on pantheism; they were, however, aware of the pantheistic tendencies of Avicenna’s other works on philosophy, and were, accordingly, reluctant to trust to his exposition of Aristotle.