Doctrine that the universe is God and, conversely, that there is no god apart from the substance, forces, and laws manifested in the universe. Pantheism characterizes many Buddhist and Hindu doctrines and can be seen in such Hindu works as the Vedas and the Bhagavadgita. Numerous Greek philosophers contributed to the foundations of Western pantheism. In the Middle Ages and the Renaissance, the tradition was continued in Neoplatonism and Judeo-Christian mysticism. In the 17th century Benedict de Spinoza formulated the most thoroughly pantheistic philosophical system, arguing that God and Nature are merely two names for one reality.