He felt now that he was not simply close to her, but that he did not know where he ended and she began.

The line describes an experience of intimacy so intense that the usual boundaries of selfhood blur. Tolstoy often portrays love not merely as attraction but as a force that reorganizes perception and identity: the lover feels “merged” with the beloved, as if personal autonomy and separateness have dissolved. The phrasing suggests both rapture and vulnerability—if one cannot tell where one ends, one’s emotional stability and moral agency may be at risk. In Tolstoy’s fiction, such fusion can be a prelude either to profound ethical awakening (a movement beyond ego) or to dependence and self-deception, depending on the relationship’s truthfulness and the character’s capacity for clear-sightedness.