What is a shared theme in the short story "Greasy Lake" and the short story "Eveline"?
The most obvious and the most significant shared theme between "Greasy Lake" and "Eveline" is that of epiphany. The concept of epiphany is an important one to James Joyce and is seen to great effect in his Dubliner stories, like "Eveline." Epiphany also is a central thematic concern in "Greasy Lake." As the friends who are attempting to prove their intimidating masculine power encounter situations that ultimately comprise a ritual of passage of rites to adulthood in which the narrator experiences an epiphany--and perhaps the others do as well since they all reject the girls' offers later the next morning.
An epiphany is a revelation or an awakening of knowledge or understanding and often relates to intuitive comprehension of something beyond what can be taught or learned. Eveline has an epiphany when the remembrance of her mother's dying words brings a new light of understanding to Eveline so that she sees her path of escape clearly. She has a second epiphany at the dock in which she sees her role at home, her promise to her dying mother, her duty to her drunkard father and her religious convictions as irrevocably important and outweighing her personal happiness. (As it happens, the second epiphany cancels the first and she is left in psychological and physical paralysis.)
The narrator of "Greasy Lake" has an epiphany about the real value of life and death when he comes literally up against death in the form of a corpse in his violence-forced immersion into a baptism by water. He has an awakening that activates his decisiveness and his ability to act on his own behalf. (Incidentally, this contrasts with Eveline's ultimate response to her two epiphanies.)