"In the Essay of the Principle of Population, Thomas Malthus wrote in the late 1700s that problems resulting from population growth were shown.
According to Malthus, an exponential increasing number of people cannot be supplied by restricted needs like food or places to live. He determines that diseases and wars are efforts to limit fast growing populations. As the author claims, poor and less educated people try to improve their circumstances by having large numbers of children, what, in his mind, leads to a worse situation in the end.
In order to solve this problem, Thomas Malthus proposes that first world countries, which already control their birth rates, should explain to poor people that producing low numbers of children will be a long-term solution for their problems.
The lecture contrasts the theory of Thomas Malthus by presenting a natural sequence of population development. Whereas Malthus classified a population either as educated or under-educated, the professor describes five Stages in population development.
According to him, all groups of people begin as poor, having a high rate of birth. In the Second stage, the quality of food and availability of medicine decreases the population mortality. Afterwards, birth rate declines in Stage Three, before declining in Stage Four with the population's high level of education. In some areas, such as Europe, the professor even determines a Stage Five, where, due to birth rates at 1.7 per couple, the number of people decreases."
Try making your sentences shorter. There is nothing wrong with short concise statements.