The present period of sociological theorizing is characterized by a diversity of theoretical approaches and perspectives. Sociological theories are necessary because without theory our understanding of social life would be very weak. Good theories help us to arrive at a deeper understanding of societies and to explain the social changes that affect us all.
A sociological perspective was made possible by two revolutionary transformations. The Industrial Revolution of the late eighteenth and nineteenth centuries radically transformed the material conditions of life and bringing with it, initially at least, many new social problems such as urban overcrowding, poor sanitation and accompanying disease and industrial pollution on an unprecedented scale.
Social reformers looked for ways to mitigate and solve such problems, which led them to carry out research and gather evidence on the extent and nature of the problems to reinforce their case for change. The French Revolution of 1789 marked the symbolic endpoint of the older European agrarian regimes and absolute monarchies as republican ideals of freedom, liberty and citizenship rights came to the fore. Enlightenment philosophers saw the advancement of reliable knowledge in the natural sciences, particularly in astronomy, physics and chemistry, as showing the way forward for the study of social life.