Using mythology to illustrate philosophical points has a lengthy tradition prior to Sartre. Achilles would have been a mythological figure by the time Zeno of Elea demonstrated the impossibility of motion by imagining a race between Achilles and a tortoise. And, in Phaedrus, Plato imagines a conversation between Thoth (from Egyptian mythology) and the Egyptian king Thamus to make a point about literacy.
Using mythology to illustrate philosophical points has a lengthy tradition prior to Sartre. Achilles would have been a mythological figure by the time Zeno of Elea demonstrated the impossibility of motion by imagining a race between Achilles and a tortoise. And, in Phaedrus, Plato imagines a conversation between Thoth (from Egyptian mythology) and the Egyptian king Thamus to make a point about literacy.