Many commentators accept Schopenhauer's claim that there are no significant changes in his thinking after 1818. I, however, argue that there are good reasons for maintaining that there are significant developments in his thought after that date and that these concern his doctrine of the thing-in-itself. Furthermore, I contend that it is Schopenhauer's increasing knowledge of and admiration for Eastern thought which provided the impetus for the changes in doctrine that occurred. I begin by outlining three significant shifts that occurred in Schopenhauer's doctrine of the thing-in-itself after 1818. I then discuss his degree of acquaintance with Eastern thought, and I suggest various similarities to and differences between Eastern teaching and Schopenhauer's doctrine. Finally, I argue that the identified shifts in Schopenhauer's doctrine of the thing-in-itself can be plausibly explained, at least in part, by his increasing familiarity with and appreciation of Eastern thought.