Genis Carreras renders various philosophical views down to pastels in predominantly geometric shapes. I’m not sure if his representation of atheism is supposed to be an upside down cross or a middle finger (or if atheism should really be represented primarily by its opposition to Christianity or to the symbolic connotations of the cross, and not as a rejection of gods more generally):
But I love this contrast:
There are many more worth perusing. Some I find misleading, some I find thought provoking. Most serve less as illustrations of philosophical positions than interpretations of them. That’s mostly a good thing.
H/T: Maria Popova, who provides larger versions of some of the posters which allow for reading the short descriptive texts given for each philosophy.