Morgan believed (1877) that all cultures passed through these stages of development, although some became "stuck" in a stage. A simpler explanation is that these 'stages' are levels of understanding achieved by a civilisation.
| Level Of Understanding | Characteristic | |
| Civilisation | Alphabet & writing | |
|---|---|---|
| Barbarism | Upper | Iron tools |
| Middle | Domestication of plants & animals | |
| Lower | Pottery | |
| Savagery | Upper | Bow & arrow |
| Middle | Fish subsistence & fire | |
| Lower | Fruit & nut subsistence | |