In order for a society to survive, the poor must execute preventative population checks so the food supply will be sustained. Population checks are necessary because a population grows exponentially while food grows linearly; therefore the population needs to be controlled for there to be enough food. There are two kinds of population checks, preventative and positive. Preventative checks are controllable impacts on population, such as a limited number of children per family, while positive checks are uncontrollable events, for example, a hurricane or a flood. Malthus suggests that without preventative checks a poor family will be in a worse state with more children, because the amount of money being brought in will be spread over more people. In addition to limiting the number of children in a family, Malthus says that men should be with one woman to help control the population. Without these checks families will run out of necessary resources, such as money and food, which will create a larger poor population. Even though population checks prevent and destroy life, they are needed to conserve the well being of the masses. For these reasons Malthus argues that the poor must put financial needs above having children to maintain their resources, and avoid poverty.