Although there has been a generally agreed interpretation of both “Caves” and “Temple” as the symbols of Hinduism, the structural relationship between the two symbols has been interpreted differently. This paper aims to elucidate the relationship between “Caves” and “Temple” by exploring how Forster’s perception of Hinduism was formed and reflected in the novel, assuming the influence of the monotheistic modern Hindu reformers, the Brahmo Samaj’s concept of “Brahman” and Plotinus’ concept of “the One” as its Western philosophical counterpart. It is found that “Caves” symbolizes “Nirguna Brahman” (Brahman without attributes), the Universal Formless God, while “Temple” symbolizes “Saguna Brahman” (Brahman with attributes), Krishna, or the eighth avatar of Vishnu. Forster represents the Marabar Caves as the nothingness of “Nirguna Brahman,” assuming that “good and evil are the same” in Hinduism, leading Adela and Mrs Moore towards moral nihilism. Forster’s representation of the Indian idea of nothingness reflects the nineteenth-century Western philosophers’ now out-dated concept of nihilism, which regards Early Buddhism’s “nirvana” (developed into “sunyata,” and later further into Advaita Vedanta’s “maya”) as the will for nothingness.