"The Greek influence never penetrated deeply into the Indic civilization... On the other hand, the West learned something from India in consequence of the communications opened up by Alexander's adventure. Our knowledge of the facts is so scanty and fragmentary that it is difficult to make positive assertions with confidence, but it is safe to say that the influence of Buddhist ideas on Christian doctrine may be traced in the Gnostic forms of Christianity, if not elsewhere. The notions of Indian philosophy and religion which filtered into the Roman empire flowed through channels opened by Alexander."