Let's say Fascism didn't appear, Mussolini just blew it really early on or is otherwise put down, the major left and centre-left parties are able to beat whichever far right groups emerge in Germany into submission, Spain may or may not be a military dictatorship. You can have a major war if you like, perhaps the Soviets decide to advance on Eastern Europe, but they do not take Berlin or anywhere west of there.
In our timeline, perhaps the greatest single event for philosophy in the previous century was WW2. The Vienna/Berlin Circle and the Frankfurt School (though very heavily defined by its opposition to Fascism in OTL) fled or were captured by the Nazis, Giovanni Gentile (Hegelian) and Heidegger (Existentialist) were some of the world's foremost philosophers and Fascists (who either are forgotten because of it or tarnished by it), philosophers such as Levinas, Sartre, Frankl, and many other great thinkers suffered greatly under Nazi rule.
Many more philosophers were greatly affected by the horrendous crimes committed by Fascism, so much of Hannah Arendt's writings can be traced to a watchful eye for totalitarianism, Camus as well among others.
What might we see without Fascism taking over a continent?
