Psychology often becomes the disease of which it should be the cure.
Marx's father became a Christian when Marx was a little boy, and some, at least, of the dogmas he must have then accepted seem to have born fruit in his son's psychology.
... the momentary state of science that may change tomorrow ...
It is clear that thought is not free if the profession of certain opinions makes it impossible to earn a living.
Common sense, however it tries, cannot avoid being surprised from time to time.