Cosmic pluralism

Cosmic pluralism, the plurality of worlds, or simply pluralism, describes the belief in numerous "worlds" (planets, dwarf planets or natural satellites) in addition to Earth (possibly an infinite number), which may harbour extraterrestrial life. The debate over pluralism began as early as the time of Anaximander (c. 610 – c. 546 BC) as a metaphysical argument, long predating the scientific Copernican conception that the Earth is one of numerous planets. It has continued, in a variety of forms, until the modern era. In Greek times, the debate was largely philosophical and did not conform to present notions of cosmology. Cosmic pluralism was a corollary to notions of infinity and the purported multitude of life-bearing worlds were more akin to parallel universes (either contemporaneously in space or infinitely recurring in time) than to different solar systems. After Anaximander opened the door to both an infinite universe and an infinite amount of universes, a strong pluralist stance was adopted by the atomists, notably Leucippus, Democritus, Epicurus—whose Epistle to Herodotus clearly lays out the Doctrine of Innumerable Worlds—and Lucretius who elaborates this Doctrine in his work De rerum natura. The Stoics posited that the universe underwent an infinite amount of cycles, expanding and contracting infinitely. Anaxarchus told Alexander the Great that there were an infinite number of worlds that each harbored an infinite variety of extraterrestrial life, leading Alexander to weep, for he had not yet conquered even one. While these were prominent thinkers, their opponents—Plato and Aristotle—had greater effect. They argued that the Earth is unique and that there can be no other systems of worlds. This stance neatly dovetailed with later Christian ideas, and pluralism was effectively suppressed for approximately a millennium. Many medieval Muslim scholars endorsed the idea of cosmic pluralism. Imam Muhammad al-Baqir (676–733) wrote "Maybe you see that God created only this single world and that God did not create humans besides you.