Theseus, Penepos, and the Eternal Labyrinth

It is well known that Theseus escaped the Labyrinth thanks to a ball of thread his loved one, Ariadne, gave to him. Let’s cut Ariadne’s thread. Because of us, Theseus has no resource to find the exit. Of course he can systematically follow each path (brute force) and retrace (backtrack) his steps when necessary… until he dies because the Labyrinth is so vast and complex.

Struck by remorse, we now want to help Theseus. The Labyrinth is so complicated that we need a miracle; that is why we send him a supernatural—at least for the moment we think he is—peer: an old blind man named Penepos. He does not seem very impressive, bent over his walking stick. But this man seems to be able to “see” things mere human beings cannot. Here he is with Theseus. He says to him, with his wavering voice and his whitish eyes: “Great Theseus, I will help you to find the path to the exit.” “Well,” replies Theseus in an English as broken as mine, “that’s adorable, Penepos, but, well, I am sorry to ask you this question, but, huh, how can you be so confident when you are not even able to see your own feet?” The old man remains silent, then says: “Doubtful Theseus, at each intersection, I will tell you if the path we face cannot lead to the exit, or may lead to the exit. And at each intersection, you have the choice to follow me, or not.” “OK, sure. I guess I have no real choice.”

And at each intersection, the old blind man confidently says that it is a dead end, even if the path seems to lead to a thousand others, or that it is a promising path. Theseus and Penepos are progressing fast despite the slow pace of the latter. Suddenly, they reach the exit. Theseus is baffled: “That is true, Penepos, you must be a demigod! You see things others cannot see. You are more useful than this stupid and fragile thread Ariadne gave to me.” “Relieved Theseus, I am neither a god nor a demigod. I am not even a mere human. Maybe I am a demihuman. I do not deserve your honors.” “But in this case, how did you manage to find the exit?” “Because it is in front of the sea.”

Theseus opens his eyes wide; Penepos blinks his. “I… I do not understand.” “We are in front of the sea, just next to the exit. It is quite windy here.” “I think I have lost the thread. Again.” “Let me explain this to you,” says the old man; “when we were in the Labyrinth, when we were facing some paths, I was unable to feel anything on my skin, but when we were facing others, I was feeling a very subtle breeze. In front of some paths, I could not hear anything. In front of others, I could hear the remote muffled murmur of the sea. Since I am blind, I have to trust my remaining senses. Thus, I knew if the path was somehow linked to the exit or not without knowing how the paths are connected together. When you are in a labyrinth, you may use a map to see how the paths are linked to each other. Because I am blind, and because we had no map, I had to trust my own representation of this territory.” “So, wait a minute. If checking the paths on the map is a simple task, and searching for the exit in the gigantic Labyrinth without a map is an impossible quest, you are telling me that we have experienced a situation where a very complex task can be solved almost as efficiently as checking if this task is done well?”

Old Penepos silently turns his face to the sea, and smiles; then, he leaves Theseus looking at the vast blue expanse with puzzled eyes.