Friedrich Hayek is the most important historical member of what is known as the "Austrian School" of economics. This is a very conservative approach to economics that is directly opposed to the ideas of John Maynard Keynes.
Hayek's major argument (in terms of political economy, at least) was that a Keynesian approach to political economy would put a country on the "road to serfdom." He believed that more government involvement in the economy would lead inexorably to socialism and to the destruction of people's freedoms. Hayek also believed that government efforts to steer the economy could not work and that only market forces could create an efficient and growing economy.
Hayek, then, was a major advocate of free market and laissez-faire policies. He did not want government to be involved in the economy because he believed that it took away freedoms and it led to a less productive economy.