Friedrich Heiler

"India is our motherland of speculative theology."...."There runs in unbroken chain from the Atman-Brahman mysticism of the Vedic Upanishads to the Vedanata of Sankara on the one side and on the other through the mystical technique of the Yoga system to the Buddhist doctrine of salvation. Another line of development equally continuous leads from the Orphic- Dionysiac mysticism to Plato, Philo and the later Hellenistic mystery cults to the Neoplatonic mysticism of the Infinite of Plotinus which is in turn is the source of the "mystical theology" of the pseudo-Dionysius the Areioagute ..... Perhaps this second chain is only an offshoot from the first, since the Elatic speculations and the cryptic doctrine of redemption have possibly borrowed essential elements from early Indian mysticism."