Claim. The four great loves — children’s love, brothers-and-sisters’ love, husband-and-wife’s love, and parents’ love — grow developmentally within each person as they mature, with later loves already present unconsciously during earlier stages.
Elaboration. Lee describes a developmental sequence for love acquisition (Four Great Realms of Heart and the Growth of Love). An infant initially does not know love, but under parents’ downward love, the infant’s love-for-parents grows — this is children’s love. (Lee specifies “infant” here means a child without yet-developed sexual consciousness; sibling relations at this stage are pre-sexual, like twins.) Then under continued parental love, brothers-and-sisters’ love begins to grow among children, in accordance with the inductive effect of love and alongside physical body growth.
When brothers and sisters mature, they marry partners from other families and become husband and wife — conjugal love also develops under the inducement of parents’ love. When mature children have completed themselves, they become parents and practice parents’ love toward their own children.
A subtle point Lee insists on: husband-and-wife’s love does not suddenly appear at marriage. As brothers and sisters grow, “a love for the opposite sex, which is a stage prior to conjugal love, grows in them little by little” — unconsciously, in vague form. Similarly, parents’ love does not suddenly appear at childbirth — children already experience parents’ love (by receiving it) and thereby know what it is like. Each later love is anticipatorily present in earlier developmental stages, even when not yet activated in its proper relation.
This matters for UT’s developmental psychology. Love is not a discrete capacity switched on at a life-stage threshold but a gradually maturing structure where all four loves are nested and emergent. It also matters for the “inclusiveness of love” claim that follows — each later love includes the earlier ones because the earlier ones developmentally constituted it.
Notably, Lee aligns this developmental picture with the broader formation-growth-completion-stages schema implicitly: love grows through phases, requires nurture, and reaches completion only at adulthood as parents. The claim is empirically testable to some degree against developmental psychology, though Lee does not engage that literature.
See also. downward-love-primary-induces-upward-and-horizontal, twelve-directions-of-divisional-love, conjugal-union-fourfold-significance