Liberalism is a political ideology which is based upon a strong belief in the importance of a human as an individual, each with individual rights. Most importantly the right to the greatest possible freedom that is consistent with the same freedom being given to everyone else.

Classic liberalism favoured the minimal state, believing that people left mostly alone would survive and prosper while maintaining a high level of individual freedom. However it was eventually realised that the industrial revolution had not created a level playing field in terms of opportunity. It was simply not possible for working class people to achieve as much as upper class people. Liberalism held that what you achieve should be relative to your effort and talents, but this was not holding true.

Hence modern liberalism favours state intervention to the extent that it is able to bring about equality of opportunity and greater social justice.