Whether Xenophanes was a monotheist, whose assertion of the unity of God suggested to Parmenides the doctrine of the unity of Being, or a pantheist, whose assertion of the unity of God was also a declaration of the unity of Being, so that he anticipated Parmenides - in other words, whether Xenophanes's teaching was purely theological or had also a philosophical significance - is a question about which authorities have differed and will probably continue to differ.
Whilst it can hardly be allowed that Xenophanes, so far from denying, actually affirms a plurality of gods, it must be conceded to Freudenthal that Xenophanes's polemic was directed against the anthropomorphic tendencies and the mythological details of the contemporary polytheism rather than against the polytheistic principle, and that, apart from the treatise De Melisso Xenophane et Gorgia, now generally discredited, there is no direct evidence to prove him a consistent monotheist.
One poet, a younger contemporary of Mahomet, has attracted much attention because his poems were religious and he was a monotheist.