Little is known of Gabirol's life. His parents died while he was a child. At seventeen years of age he became the friend and protégé of Jekuthiel Hassan. Upon the assassination of the latter as the result of a political conspiracy, Gabirol composed an elegy of more than 200 verses. The death of Hai Gaon also called forth a similar poem. When barely twenty Gabirol wrote Ana?, a versified Hebrew grammar, alphabetical and acrostic, consisting of 400 verses divided into ten parts. Of this grammar, ninety-five lines have been preserved by Solomon Par?on. In these Gabirol reproaches his townsmen with their neglect of the Hebrew language.

Gabirol's residence in Zaragoza was embittered by strife. He thought of leaving Spain, but remained and wandered about. He gained another friend and patron in the person of Samuel ibn Naghrela, whose praises he sang. Later an estrangement arose between them, and Naghrela became for a time the butt of Gabirol's bitterest irony. All testimonies agree that Gabirol was comparatively young at the time of his death, which followed years of wandering. The year of his death was probably 1058 or 1059.

A legend concerning the manner of Gabirol's death is related by Ibn Ya?ya in "Shalshelet ha-Kabbalah." In this legend, a Muslim poet, jealous of Gabirol's poetic gifts, killed him, and buried him beneath the roots of a fig tree. The tree bore fruit abundantly; and the fruit was of extraordinary sweetness. This strange circumstance excited attention; a search was instituted, the remains of the murdered Gabirol were brought to light, and the murderer expiated his crime with his life.

Gabirol was one of the first teachers of Neoplatonism in Europe. His role has been compared to that of Philo. Philo had served as the intermediary between Hellenic philosophy and the Oriental world; a thousand years later Gabirol Occidentalized Greco-Arabic philosophy and restored it to Europe.

"Fons Vitæ" (i.e., ; Ps. xxxvi 10) is a philosophical dialogue between master and disciple. The book derives its name from the fact that it considers matter and form as the basis of existence and the source of life in every created thing. It was translated from the Arabic into Latin in the year 1150. There are no extant Arabic texts, but the Latin text has been translated into Hebrew.

In 1846 Solomon Munk discovered among the Hebrew manuscripts in the Bibliothèque Nationale, Paris, a work by Shem-Tov ibn Falaquera, which, upon comparison with a Latin manuscript of the "Fons Vitæ" of Avicebron (likewise found by Munk in the Bibliothèque Nationale), proved to be a collection of excerpts from an Arabic original of which the "Fons Vitæ" was evidently a translation.

Munk concluded that Avicebron or Avencebrol, who had for centuries been believed to be a Christian scholastic philosopher, was identical with the Jew Ibn Gabirol.

In the Fons Vitæ, or "Fountain of Life" (), Gabirol aims to outline but one part of his philosophical system, the doctrine of matter and form: hence the "Fons Vitæ" also bore the title "De Materia et Forma." The manuscript in the Mazarine Library is entitled "De Materia Universali."

The "Fons Vitæ" consists of five tractates, treating respectively of (1) matter and form in general and their relation in physical substances ("substantiæ corporeæ sive compositæ"); (2) the substance which underlies the corporeality of the world ("de substantia quæ sustinet corporeitatem mundi"); (3) proofs of the existence of "substantiæ simplices", of intermediaries between God and the physical world; (4) proofs that these "substantiæ simplices", or "intelligibiles", are likewise constituted of matter and form; (5) universal matter and universal form.

The chief doctrines of the "Fons Vitæ" may be summarized as follows:

• (1) All created beings are constituted of form and matter.

• (2) This holds true of the physical world, of the "substantiis corporeis sive compositis", and is not less true of the spiritual world, of the "substantiis spiritualibus sive simplicibus", which latter are the connecting-link between the first substance, "essentia prima", that is, the Godhead, and the "substantia, quæ sustinet novem prædicamenta", that is, the substance divided into nine categories...in other words, the physical world.

• (3) Matter and form are always and everywhere in the relation of "sustinens" and "sustentatum", "propriatum" and "proprietas", substratum and property or attribute.

The main thesis of the "Fons Vitæ" is that all that exists is constituted of matter and form; one and the same matter runs through the whole universe from the highest limits of the spiritual down to the lowest limits of the physical, excepting that matter the farther it is removed from its first source becomes less and less spiritual. Gabirol insists over and over again that the "materia universalis" is the substratum of all that exists.

Ibn Gabirol holds that everything that exists may be reduced to three categories: the first substance, God; matter and form, the world; the will as intermediary. Gabirol derives matter and form from absolute being. In the Godhead he seems to differentiate "essentia", being, from "proprietas", attribute, designating by "proprietas" the will, wisdom, creative word ("voluntas, sapientia, verbum agens"). In reality he thinks of the Godhead as being, and as will or wisdom, regarding the will as identical with the divine nature. This position is implicit in the doctrine of Gabirol, who teaches that God's existence is knowable, but not His being or constitution, no attribute being predicable of God save that of existence.

It is held by some scholars that Ibn Gabirol set out to reconcile Neoplatonism with Jewish theology. Geiger finds complete harmony between Gabirol's conception of the Deity and the historical Jewish conception of God; and Guttmann and Eisler hold that in Gabirol's doctrine of the will there is a departure from the pantheistic emanation doctrine of Neoplatonism and an attempted approach to the Biblical doctrine of creation.

A suggestion of Judaic monotheism is found in Gabirol's doctrine of the oneness of the "materia universalis." The Neoplatonic doctrine that the Godhead is unknowable naturally appealed to Jewish rationalists, who, while positing the existence of God, studiously refrained from ascribing definite qualities or positive attributes to God.

Ibn Gabirol strived to keep "his philosophical speculation free from every theological admixture." In this respect Gabirol is unique. The "Fons Vitæ" shows an independence of Jewish religious dogma; not a verse of the Bible nor a line from the Rabbis is cited. For this reason Gabirol exercised comparatively little influence upon his Jewish successors, and was accepted by the scholastics as a non-Jew, as an Arab or a Christian. The suspicion of heresy which once clung to him prevented Ibn Gabirol from exercising a great influence upon Jewish thought. His theory of emanation was held by many to be irreconcilable with the Jewish doctrine of creation; and the tide of Aristotelianism turned back the slight current of Gabirol's Neoplatonism.

Moses ibn Ezra is the first to mention Gabirol as a philosopher. He speaks of Gabirol's character and attainments in terms of highest praise, and in his "'Aruggat ha-Bosem" quotes several passages from the "Fons Vitæ." Abraham ibn Ezra, who gives several specimens of Gabirol's philosophico-allegorical Bible interpretation, borrows from the "Fons Vitæ" both in his prose and in his poetry without giving due credit.

Abraham ibn Daud of Toledo, in the twelfth century, was the first to take exception to Gabirol's teachings. In the "Sefer ha-Kabbalah" he refers to Gabirol as a poet in complimentary phrase. But in order to counteract the influence of Ibn Gabirol the philosopher, he wrote an Arabic book, translated into Hebrew under the title "Emunah Ramah", in which he reproaches Gabirol with having philosophized without any regard to the requirements of the Jewish religious position, and bitterly accuses him of mistaking a number of poor reasons for one good one.

Occasional traces of Ibn Gabriol's thought are found in some of the Kabbalistic literature of the thirteenth century. Later references to Ibn Gabirol, such as those of Eli ?abillo, Isaac Abarbanel, Judah Abarbanel, Moses Almosnino, and Joseph Solomon Delmedigo, are based upon an acquaintance with the scholastic philosophy, especially the works of Aquinas.

Though Gabirol as a philosopher was not studied by the Jewish community, Gabirol as a poet kept alive the remembrance of the ideas of the philosopher; for his best-known poem, Keter Malkut , is a philosophical treatise in poetical form, the "double" of the Fons Vitæ. Thus the eighty-third line of the poem points to one of the teachings of the "Fons Vitæ"; viz., that all the attributes predicated of God exist apart in thought alone and not in reality.

Berachyah, a Jewish philosopher, drew upon Gabirol's works in his encyclopedic philosophical text Sefer Hahibbur (The Book of Compilation).

Abundant compensation awaited Ibn Gabirol in the treatment accorded him by the Christian world. Regarded as the work of a Christian philosopher, it became a bone of contention between the Platonist Franciscans led by Duns Scotus, who supported Gabirol, and the Aristotelian Dominicans led by St. Albertus Magnus and St. Thomas Aquinas.

A sign of influence by Ibn Gabirol is found in the works of Dominicus Gundisallimus, who not merely translated the Fons vitæ into Latin, but incorporated the ideas of Gabirol into his own teaching. William of Auvergne refers to the work of Gabirol under the title "Fons Sapientiæ." He speaks of Gabirol as a Christian, and praises him as "unicus omnium philosophantium nobilissimus." Alexander of Hales and his disciple Bonaventura accept the teaching of Gabirol that spiritual substances consist of matter and form. William of Lamarre is likewise a defender of Gabirolean doctrine.

The most zealous of the champions of Gabirol's theory of the universality of matter is Duns Scotus, through whose influence the basal thought of the Fons Vitæ, the materiality of spiritual substances, was perpetuated in Christian philosophy, influencing later philosophers even down to Giordano Bruno, who refers to "the Moor, Avicebron."

The main points at issue between Gabirol and Aquinas were three: (1) the universality of matter, Aquinas holding that spiritual substances are immaterial; (2) the plurality of forms in a physical entity, which Aquinas denied; and (3) the power of activity of physical beings, which Gabirol affirmed. Aquinas held that Gabirol made the mistake of transferring to real existence the theoretical combination of genus and species, and that he thus came to the erroneous conclusion that in reality all things are constituted of matter and form as genus and species respectively.

The Improvement of the Moral Qualities is an ethical treatise which has been called by Munk "a popular manual of morals." It was composed by Gabirol at Zaragoza in 1045, at the request of some friends who wished to possess a book treating of the qualities of man and the methods of effecting their improvement. In two respects the "Ethics" (by which abbreviation the work may be cited) is highly original.

Gabirol set out to systematize the principles of ethics independently of religious dogma. His treatise is original in its emphasis on the physio-psychological aspect of ethics, Gabirol's fundamental thesis being the correlation and interdependence of the physical and the psychical in respect of ethical conduct.

Gabirol's theses may be summed up as follows: The qualities of the soul are made manifest through the senses; and these senses in turn are constituted of the four humors. Even as the humors may be modified one by the other, so can the senses be controlled and the qualities of the soul be trained unto good or evil. Though Gabirol attributes the virtues to the senses, he would have It distinctly understood that he treats only of the five physical senses, not of the "concealed" senses, such as perception and understanding, which partake of the nature of the soul. In order to cultivate his soul, man must necessarily know its peculiarities, study himself as he is, closely examine his character and inclination, habituate himself to the abandonment of whatever is mean, i.e., whatsoever draws him into close contact with the physical and temporal, and aim at the spiritual and the abiding. This effort in itself is blessedness. A man's ability to make such an effort is proof of divine benevolence.

Next follows the most original feature of Gabirol's ethical system, the arrangement of the virtues and vices in relation to the senses: every sense becoming the instrument, not the agent, of two virtues and two corresponding vices.