How did intellectual developments reflect the general crisis in western thought?

One development was mass secularization. People abandoned the idea of there being a god and turned more and more towards atheistic or agnostic beliefs. This was highly problematic for western thought which was commonly very theistic and its ethics were often based on concepts from religion and with loss of this the western thought was endangered.

Another is that nihilism started developing. Nihilism is the concept that life in itself is meaningless and that there is nothing truly to strive for or do since there is no true meaning to be found in it other than the meaning that we ascribe to it which is not true since it was created by us and not by a higher power.

Another was scientific development of the atoms and theory of atoms. These developments very soon started getting weaponized and this led to the nuclear bombs which put the entire world in a crisis and on the brink of war, not just western thought. This also sparked numerous new ideas regarding ethics and morality.

Another was the development of Freudian psychology and psychoanalysis. This led to a crisis because it explained that people are not truly responsible for what they do but that they are guided by their subconscious and it is not something that we can explain. This led to numerous ideas regarding concepts of free will.