The Unbearable Lightness of Being by Milan Kundera
Living for Sabina meant seeing. Seeing is limited by borders: strong light, which blinds, and total darkness. Perhaps that was what motivated Sabina's distaste for all extremism. Extreme borders beyond which life ends, and a passion for extremism, in art and politics, is a veiled longing for death.
In Franz the word "light" did not evoke the picture of a landscape basking in the soft glow of day; it evoked the source of light itself: the sun, a light bulb, a spotlight. Franz's associations were familiar metaphors: the sun of righteousness, the lambent flame of the intellect, and so on.
Darkness attracted him as much as light. He knew that these days turning out the light before making love was laughable, and so he always left a small lamp burning over the bed. At the moment he penetrated Sabina, however, he closed his eyes. The pleasure suffusing his body called for darkness. That darkness was pure, perfect, thoughtless, visionless; that darkness was without end, without borders; that darkness was the infinite we each carry within us.
(Yes if you're looking for infinity, just close your eyes.)
And at the moment he felt pleasure suffusing his body, Franz himself disintegrated and dissolved into the infinity of his darkness, himself becoming infinite. But the larger a man grows inside his own inner darkness, the more his outer from diminishes. A man with closed eyes is a wreck of a man. Then, Sabina found the sight of Franz distasteful, and to avoid looking at him she too closed her eyes. But for her, darkness did not mean infinity; for her, it meant a disagreement with what she saw, the negation of what was seen, the refusal to see.