The concept of soul in Jewish tradition derives from Genesis, where God endows humans with "spirit or breath" (ruah). Initially, this spirit was "inseparably connected, if not wholly identified, with the life-blood." Contact with Persian and Greek philosophy introduced the idea of a disembodied soul with individual identity, appearing in later biblical texts like Proverbs and Ecclesiastes.
Three Hebrew terms describe the soul: "ruah" (spirit in primitive state), "nefesh (the vital soul)" (spirit associated with body), and "neshamah (the higher soul)" (spirit active in the body). The Apocrypha explicitly states that "All souls are prepared before the foundation of the world," establishing the doctrine of preexistence. Different souls possess varying qualities, and the body serves as a temporary vessel for the soul during earthly life.
Philo Judaeus, the Alexandrian Jewish philosopher, synthesized Biblical interpretation with Platonic psychology. He identified the three Hebrew soul-terms with Plato's tripartite soul: rational (seated in the head), spiritual (in the chest), and desiring (in the abdomen).
The rational mind (nous) represents divine essence—"a fragment of the Divinity" that is preexistent and immortal. This mind transcends bodily limitations, operating through independent spiritual powers rather than directly. Sensory perception requires mediation between mind and senses through pleasure (symbolized biblically by the serpent).
Talmudic scholars rejected the notion that souls sin before incarnation, instead teaching perfect bodily purity. The daily morning prayer affirms: "My God, the soul which Thou didst place in me is pure." This represented protest against Platonic doctrines of preincarnate transgression.
The Rabbis maintained consistent body-soul dualism while rejecting Platonic preexistence. According to Talmudic teaching, all souls were "formed during the six days of Creation," existing in paradise and present at Sinai. Souls enter embryos through divine appointment, supervised by angels. The soul's entry occurs either at conception or after embryonic formation—a point of rabbinic debate.
The Talmud compares body and soul to a city and its inhabitants. Notably, souls ascend during sleep, receiving dream communications. Some advanced rabbis explained dreams psychologically rather than supernaturally.
The distinction between "spirit" (ruah) and "soul" (nefesh) appears consistently in rabbinical literature. Friday Sabbath observance involved receiving an additional individual soul, which returned at the Sabbath's conclusion.
The Rabbis established parallels between soul and God: as the world fills with divine presence, the body fills with soul; as God sees without being seen, so the soul perceives invisibly. The "yezer Tob" (good inclination) and "yezer ha-ra'" (evil propensity) represent moral forces, with the soul bearing responsibility for ethical conduct.
Saadia Gaon systematically addressed soul philosophy in his "Emunot we-De'ot." He argued the soul was "created by God at the same time as the body," with substance resembling celestial spheres but finer in quality. Three latent powers activate through bodily union: intelligence, passion, and appetite—belonging to one indivisible soul seated in the heart.
Saadia opposed Plato's preexistence doctrine, arguing that bodily union advantaged the soul, enabling paradise access through obedience. Fire requires fuel; similarly, the soul needs the body's instrumentality for spiritual achievement.
Neoplatonic influence pervaded tenth and eleventh-century Jewish thought. Bahya ibn Pakuda proposed three distinct souls: vegetative (matter-derived), animal (matter-derived), and rational (emanating from active intellect). The rational soul's ray penetrates the embryo, supervising vegetative and animal development.
Ibn Gabirol and Joseph ibn Zaddik similarly asserted three distinct souls. Their respective attributes were: vegetative (chastity), animal (energy), and rational (wisdom), collectively producing justice.
Jewish Peripatetics, particularly Maimonides, adopted Aristotelian psychology: the soul as unified entity with five faculties—nutritive, sensitive, imaginative, appetitive, and rational. Each faculty comprehends inferior ones potentially. The intellect operates theoretically (discerning truth/falsehood) or practically (judging good/evil, exciting will).
Maimonides held that the soul, constituting bodily form, remains indissolubly united with it. Upon death, all faculties cease—except the "acquired intellect" (knowledge obtained through study), which constitutes real substance and survives independently.
Levi ben Gershon followed Maimonidean psychology but differentiated human knowledge into three classes: sensory perception of individuals, abstraction producing generalities, and reflection concerning God and angels. He contended that generic forms exist independently "ante rem" in the universal intellect, and mathematical theories constitute real substances contributing to acquired intellect.
Crescas attacked the acquired intellect principle philosophically and theologically. He questioned how something created during lifetime achieves immortality, and if only acquired intellect survives bodily death, what entity experiences reward or punishment? If the soul ceases existing, what enjoys paradise? Crescas proposed that the soul, though constituting bodily form, represents spiritual substance wherein thinking exists potentially—preserving soul continuity through death.
Zoharic psychology demonstrates Neoplatonic influence within mystical frameworks. The soul originates in Supreme Intelligence, the "universal soul" containing forms distinguishing all living existences. All souls were "formed" and "prepared to be given" to future humans, observed by God in their destined forms.
The soul comprises three elements: rational (neshamah), moral (ruah), and vital (nefesh)—emanations from Sefirot (the divine emanations), each possessing ten potencies subdivided into trinities. The rational element connects humans to the intellectual world through the Crown Sefirah (a divine emanation); the moral element connects to the moral world through Beauty; the vital element connects to the material world through Foundation.
Two additional soul-elements exist: one inherent in the body without mingling, serving as intermediary; another uniting body and soul. At conception, the Zohar teaches, "the Holy One sends on earth an image engraved with the Divine Seal," presiding over human formation, growing with the person, and departing at death.
Male and female souls emanate from masculine and feminine Sefirot respectively, paired before earthly descent but separated upon incarnation. The Zohar compares soul elements to a burning lamp's flame: the dim light (vital element) springs from burning material below; the white light (moral element) struggles upward while remaining connected; the invisible flame-top (rational element) actually disengages and rises independently.
Human souls descend into bodies because of their finite nature, uniting with flesh to contemplate creation, achieve self-consciousness, and eventually return to God—the "inexhaustible fountain of light and life."