Comment by nebolo

I am not sure I understand your use of the word "symptom". Being syncretistic, by itself, is clearly not indicative of fascism (as you point out all religion is syncretistic to some extent, so is art, etc.), but if you see many of the symptoms that Eco describes - not just syncretism, but also traditionalism, irrationalism, uniformity of thought, fear of difference, populism, nationalism, etc. - then syncretism becomes part of your "fascism" diagnosis. By themselves these things can be part of various strands of political thought, only together are they Ur-Fascism.

Just like a headache, by itself is not indicative of a disease, but can be a clue in combination with other symptoms.