Karl Marx is was one of the most important thinkers of the 19th century. He wrote brilliantly on subjects such as philosophy, political science, economics and history. He never called himself a sociologist, but his work is very rich in sociological insights. Hence he is regarded as one of most profound and original sociological thinkers. His influence has been tremendous. Millions of people throughout the world accept it theories with almost religious fervour.
Marx believed that the task of the social scientist was not merely to describe the world, it was to change it. Whereas Spencer saw social harmony and inevitability of progress, Marx saw social conflict and the inevitability of revolution. The key of history, he believed is class conflict the bitter struggle between the capitalist and the labours or between those who own the means of producing wealth and those who do not. Marx also believed that the historic struggle would end only with overthrow of the ruling exploiters, and the establishment of a free, harmonious, classless society. Marx placed too much emphasis on the economic base of society. Marx thought that the economic base of the society influence the general character of all other aspects of culture and social structure, such as law, religion, education, government etc.
Modern sociologists thought reject many teachings of Marx, do generally recognise the fundamental influence of the economy on other areas of society. The 'conflict approach' to the study of social phenomena devoted by Marx is still in currency. Later sociologists and social thinkers could hardly escape the influence of Marxian ideas and theories. Great number of writers and thinkers still subscribe to his views and theories.