  Unlike most other early philosophers, Heraclitus is usually seen as independent of the several schools and movements later students (somewhat anachronistically) assigned to the ancients, and he himself implies that he is self-taught (B101). He has been variously judged by ancient and modern commentators to be a material monist or a process philosopher; a scientific cosmologist, a metaphysician, or a mainly religious thinker; an empiricist, a rationalist, or a mystic; a conventional thinker or a revolutionary; a developer of logic or one who denied the law of non-contradiction; the first genuine philosopher or an anti-intellectual obscurantist. No doubt the sage of Ephesus will continue to remain controversial and difficult to interpret, but scholars have made significant progress in understanding and appreciating his work.