Are you familiar with Hermann Poppelbaum's article in the Journal of Anthroposophy from 1970? Its title is: Can Supersensible Facts Be Proven? It proves to be the clearest evidence next to Steiner himself that the only "blind spot" is our own resistance to making ourselves into the instrument of spiritual research based on the path of Pure Thinking. Steiner covers it in OOS, chapter 5, under the heading of, "sense-free thinking", and this article of Poppelbaum backs it up.
Are you familiar with Hermann Poppelbaum's article in the Journal of Anthroposophy from 1970? Its title is: Can Supersensible Facts Be Proven? It proves to be the clearest evidence next to Steiner himself that the only "blind spot" is our own resistance to making ourselves into the instrument of spiritual research based on the path of Pure Thinking. Steiner covers it in OOS, chapter 5, under the heading of, "sense-free thinking", and this article of Poppelbaum backs it up.
https://www.sophiainstitute.us/blog/can-supersensible-facts-be-proven