4 ideas
In the Great Unity age, the world (tianxia) is treated as a public trust rather than a family possession, so rulers are selected for worthiness and ability instead of inheriting power. Public office is defined by merit and a duty of service, not by lineage or private ownership.
People in the ideal age do not treat only their own parents as parents or only their own children as children. Care is organized by need across the whole society: the old are supported to the end of their lives, the able-bodied are employed, the young are raised, and widows, orphans, the childless, and the disabled are all provided for.
The passage says people dislike seeing goods wasted on the ground, yet they do not store them up for themselves. People also dislike leaving their strength unused, yet they do not exert it only for their own benefit. Under this lens, the moral test of an economy is whether resources and effort circulate to common use rather than whether they are privately accumulated.
When people practice trustworthiness and cultivate harmony, scheming is shut off and theft and rebellion do not arise, so outer doors can be left unlocked. On this view, security comes from social trust and a fair distribution of care rather than from coercion or physical barriers. The passage then presents the later 'Lesser Prosperity' age of family property and ritual rules as a decline from this state.