Would you like a direct quote from a specific edition, or a more detailed breakdown of the depressive position and the formation of conscience?

It seems you’re referencing on the development of conscience in the child, specifically her ideas around love, guilt, and reparation — likely from her 1937 paper “Love, Guilt and Reparation” (later included in her collected writings). The number “252” might refer to a page in a specific edition, such as Love, Guilt and Reparation and Other Works 1921–1945 (the Hogarth Press edition, or the Vintage edition from 1998).