Final answer:
Prometheus's gift to mankind was fire, a symbolic representation of knowledge and technological progress that differentiates humans from animals and sparks the development of civilization.
Step-by-step explanation:
The gift Prometheus gave to men was fire. This mythical figure is known for his intelligence and for defying the gods by stealing fire from Olympus to give it to mankind. This act enabled humans to progress, develop civilization, and become independent. The gift of fire is often interpreted symbolically as the spark of knowledge and the beginning of human mastery over the natural world, which links to the advent of technology and culture. Furthermore, Prometheus' tale is reflected as a narrative of human resilience and ingenuity, as the fire also signifies the light of reason that separates humans from animals.