“It is as his own mind comes into contact with others that truth will begin to acquire value in the child's eyes and will consequently become a moral demand that can be made upon him.”

Source: The Moral Judgment of the Child (1932), Ch. 2 : Adult Constraint and Moral Realism <!-- p. 165 -->
Context: !-- Every thought that enters the head of a child of 2-3 does so from the first in the form of a belief and not in the form of a hypothesis to be verified. Hence the very young child's almost systematic romancing as with others and to which one cannot yet give the name of pseudo-lie, so close is the connection between primitive romancing and assertive belief.
Hence finally, the pseudo-lie, which is a sort of romancing used for other people, and serving to pull the child out of any straight due to circumstances, from which he deems it perfectly natural to extricate himself by inventing a story. Just as, from the intellectual point of view the child will elude a difficult question by means of an improvised myth to which he will give momentary credence, so from the moral point of view, an embarrassing situation will give rise to a pseudo-lie. Nor does this involve anything more than an application of the general laws of primitive child thought, which is directed towards its own satisfaction rather than to objective truth. -->It is as his own mind comes into contact with others that truth will begin to acquire value in the child's eyes and will consequently become a moral demand that can be made upon him. As long as the child remains egocentric, truth as such will fail to interest him and he will see no harm in transposing facts in accordance with his desires.