Although Gersonides was critical of his Aristotelian forebears, and often worked hard to undermine their theories, he was nevertheless committed to constructing a positive scientific understanding of the world. Hasdai Crescas, in contrast - chief rabbi of the Jews of Aragon, legal scholar, polemicist, and theologian - mastered Aristotelianism for a different reason: to topple it from within. Through his careful study of the massive corpus of philosophical texts available in Hebrew, he set out, in his Light of the Lord, to free Judaism from the doctrines of Aristotle and his Jewish epigones. In particular, he focused his attention on philosophical proofs for the existence, unity, and incorporeality of God (and the Aristotelian principles upon which they were based), philosophical ideas about the origin of the world, divine knowledge of individuals, prophecy as a natural perfection, providence as consequent upon the intellect, and - most important for our purposes - the noetic doctrine of immortality, achieved through conjunction with the active intellect.
The main discussion of intellect and immortality in Light of the Lord is found in Book 2, Part 6, where Crescas first presents a summary of the Aristotelian theory of knowledge and conjunction - based mainly on Jewish adaptations - followed by a refutation of it. The ideas of the philosophers, as Crescas understands them, are as follows: through the acquiring of true knowledge, the human or potential or material intellect can become constituted as an incorporeal substance, called the ‘‘acquired intellect,’’ which will exist forever. This state of existence, this achieving of knowledge, is considered by them the final aim of human existence; and the intellect’s eternal contemplation of universal truths after death is what it means to be truly happy: it brings with it true beatitude and leads to the highest form of pleasure.
How one can achieve this state of intellectual bliss, however, is not entirely clear. For Crescas, there are two different ways of understanding it. First, the view that knowledge of any truth whatsoever will lead to some degree of acquired intellect and some level of immortality. This idea, which Crescas seems to draw from Gersonides, is dependent on the view that intelligible forms in the sublunar world are part of the plan or order or ‘‘nomos’’ in the active intellect, thus to know any part of the plan is to know a part of the active intellect. According to this opinion, the more knowledge one attains the greater one’s pleasure and larger one’s share in eternal bliss. The second view - which Crescas seems to draw from Maimonides - is that the intellect can become constituted as an incorporeal eternal substance only when it contemplates an incorporeal separate intelligence, such as God, the angels, or the active intellect; conjunction requires knowledge of the intelligence itself, not any part or instantiation of it.
The philosophical theory of conjunction - no matter which way it is construed - is, for Crescas, not only incoherent but also dangerous. First, if one achieves some share in immortality simply by knowing any rational truth, then anyone can attain it. Reason and philosophy, moreover, would seem to be superior to revelation and law, for it is through thinking, not through acting and obeying, that final reward is achieved. The second theory is no less problematic - on different grounds. The problem is that, according to Maimonides, knowledge of God (and apparently all incorporeal substances) is possible only through negation, and negative knowledge, knowing what God, the angels, or the active intellect is not, cannot lead to any positive identification between knower and known. By knowing what is not the active intellect one is not led to any union with the active intellect. If conjunction with the active intellect requires complete and positive knowledge of the active intellect, and knowledge of the active intellect is impossible, then conjunction is impossible. Or, to modify slightly an infamous conclusion attributed to al-Farabl: immortality of the soul is nothing but an old wives’ tale.
Crescas has another argument as well, which is more creative, and which, in many ways, leads more directly to his own opinion on the subject. If the final aim of human existence, he argues, is knowledge and intellectual cognition, which constitutes the intellect as a separate incorporeal substance, then the final aim of man is to become not-man. That is, the final aim of man as composite of form and matter is to become pure intellect, completely separate from matter. Not only is this incoherent, he concludes, but it is in violation of divine justice, for how can the intellect alone, existing eternally, joyfully contemplating universal truths, receive this reward for what was accomplished by the human being during life, as body and soul.
What then is the final aim of human existence, according to Crescas? And if immortality is possible, and not trivial, what is it and how is it achieved? Here Crescas draws more from Scripture and tradition to present a theory contrary to that of the philosophers. For him the soul is a self-subsisting spiritual substance disposed toward thinking. That is, the soul is not a substrate, which serves and is subordinate to intellect; rather thinking or intellectual cognition is just one of several things that contribute to the happiness of the soul - which is the final perfection. In fact, thinking is itselfsubordinate to action, to obedience to the law and observance of the commandments, by which love - the highest ideal and truest happiness, is achieved. As the Rabbis say: ‘‘Which is better, study or action? Study, because it leads to action.’’ This is why eternal reward is achieved even by the minor child who does nothing more than say amen after the communal prayers.
Crescas’ critique of the Aristotelian ideas of acquired intellect and conjunction with the active intellect had varying success. It was used, borrowed, modified, and developed by a host of students and followers during the fifteenth century, including Joseph Albo; and it was rejected by others, such as Abraham Shalom, who attempted to defend Maimonides and Gersonides against Crescas’ attacks. As in other areas of Crescas’ philosophy, perhaps here also it was only in Renaissance and early modern times when his ideas were fully appreciated - for example, in the philosophy of love of Judah Abarbanel or the intellectual love of God of Spinoza.
See also: > Abu l-Barakat al-Bajgdad! > Alexander of Aphrodisias and Arabic Aristotelianism > Aristotle, Arabic > Avicebron > Consciousness > Contemplative
Happiness and Civic Virtue > Dominicus Gundissalinus
> Doxographies, Graeco-Arabic > al-FarabI, Abu Nasr
> Galen, Arabic > al-(GazalI, Abu Hamid Muljammad
> Gersonides > Happiness > Hasdai Crescas > Ibn Bajja, Abu Bakr ibn al-Sa’ijg (Avempace) > Ibn Sina, AbU ‘All (Avicenna) > Ibn Tufayl, Abu Bakr (Abubacer)
> Internal Senses > Isaac Israeli > Judah Halevi
> al-Kindl, AbU YUsuf Ya‘qub ibn Isljaq > Knowledge
> Moses Maimonides > Parva naturalia, Commentaries On Aristotle’s > Philosophical Psychology > Plato, Arabic
> Plotinus, Arabic > Saadia Gaon > Themistius, Arabic
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