Eight people, working in a village. They exchange products. Money is developed as a measure: one cow = two sheep = a set of clothes = 1 unit of money (eg Euro). Peter and Susan were nervous types, so they saved money just in case their cows got foot and mouth. Paul and Angela, on the other hand, toolmakers, lived for the moment, and had spent their money before they had even got it! So they became short of money and the village could not let them starve or else the village would have no more decent tools. So Peter and Susan generously volunteered to lend them some money – against a share in their tool-making firm – and Paul and Angela got back to work.
Before long, Peter and Susan’s share in the the tool-making firm had become full ownership. In time, the same thing applied to many of the other industries in the village, and its land, and Peter and Susan had accumulated property.
The state apparatus followed.