Malthus believed that two checks: Preventive check and positive check help to control population growth. Preventive check usually involves moral restraint where a person chooses to practice abstinence, or delays marriage until one's financially able. In some cases, one could also be prevented from marriage or conjugation by the direct influence of others. While positive check talks about war, epidemic, diseases and more. These two checks, according to Malthus, help to keep population growth on at bay.