Should Philosophies Be Evaluated on the Basis of Accuracy of Knowledge or on Potential Effects?
When I am speaking of the question of 'dangerous' ideas, like the Nazi's on one hand and the question of knowledge as questionable I am probably referring to conflicts in assumptions which have appeared historically. These have been tensions arising at different juncture and are connected to a mixture of fear and changing knowledge, especially in the rise of scientific discovery.
Some of the tensions may be due to the interplay within science and religion. This may have been based on the rise of humanism. Sometimes people speak of humanism as if it is identical with secular humanism. It is not as simple because it goes much further back and was interconnected to a lot of debate which emerged linked to theism and atheism, as well as agnosticism. There was also the conflict between rationalism, which was emerging in science and the romantic movement, from which Nietzsche's thinking stems.
The Nazi movement was connected to the development of ideas within Germany which may have been more related to cultural tensions, especially between Germans and Jews. It is likely that this provided a ground from which certain ideas could have been grasped in support. Hitler was influenced by theosophy and, Jung, who had an interest in the esoteric also wrote some ideas which adopted the view of the superiority of the German race. His own disagreement with Freud was also relevant in the context of the friction between Jews and Germans. Even though Hitler is the figurehead of this, the tension was about implicit cultural war
Also, the emphasis on the distinction between the right and left path is probably related to the political aspects of esotericism. Certain ideas may have been in the hands of the privileged elite and in the hands of organisations such as the Rosrucians. In addition, the emphasis on development of one's potential in esoteric thought may have been discouraged because it goes beyond the following of groupthink and is about exploration.
When I speak of the various 'dangers' it is in the context of many human beings having access to so many ideas so easily. If anything, the biggest danger may be one of confusion. In addition, one's own psychological state may come into play. For example, when I got particularly depressed by nihilism it was in the time of lockdown. So, it is not just about ideas 'out there' but in relation to one's own experience and circumstances.