1. population is inevitably limited by means of subsidence
2. population increases with increase in means of subsistence unless prevented by power checks
3. checks that inhibit reproductive capacity are
1. private= late marriage, abstinence, celibacy
2. destructive = war, poverty, disease, famine
4. Malthusian catastrophe
1. population exceeds food production
2. return to subsistence - level conditions
3. no time frame