If you read Bertrand Russell's History of Western Philosophy, he takes rather dim view of Marcus Aurelius, and specifically doubts the seriousness of his writings and ideas, considering them somewhat dubious.
Russell himself makes false and dubious claims in that book (for example, claims about Aristotle/Aristotelianism, which he hated). I don't regard him to be an especially reliable or objective expositor of philosophy or philosophical history, generally speaking.
