In political philosophy and cultural studies, certain thinkers from the twentieth-century stand out for their reliance upon distinguishing between open and closed selfhood. It is a long-running theme throughout the history of western philosophy. Yet, I have encountered Eric Voegelin who writes on it in On the Form of the American Mind (1928), then Henri Bergson relies upon the open vs. closed societies analysis in The Two Sources of Morality and Religion (1932). Finally, American philosopher 1948 Charles Morris penned the book The Open Self in 1948 mentioning neither Voegelin nor Bergson. Open selfhood has fallen into obscurity for many and the distinction has largely vanished from political and public discourse.
Are there any other sources--aside from Karl Popper's The Open Society and its Enemies (1945), who was never cited by Morris in 1948 either--related to the questions, values, and issues of the open self versus the closed self? Do we find any more explicit examples throughout the philosophical literature?