What is the difference between classical liberals and new liberals?

Classical liberals believe that society should place the freedom of the individual at it's core. They believe that to do so the government, or state, should not interfere in the lives of individuals. Rather, they should allow them to make whatever decisions they please, providing they don't infringe upon the free decisions and actions of others. This sort of freedom is called negative freedom and was put forth by Isiah Berlin. It is 'freedom from' any external influence that underpins classical liberalism. This is in contrast to modern or new liberals, who still believe that society should be based upon the freedom of the individual, however the means through which that freedom is protected is different for the new liberal. Instead of supporting the negative conception of freedom, modern liberals support positive freedom (also put forth by Berlin), which argues that for the individual to be free, they must be given the freedom to do so something.

This belief in positive freedom means in practice, a modern liberal will support the state enabling people to reach their potential and live free lives. The classical liberal on the other hand, because they support a negative idea of freedom, wish to see the state take a step back and not interefere at all in the lives of individuals. For example, modern liberals will argue for social welfare protection to enable poorer individuals to have the financial freedom to make the purchases they would like to, or need to. Classical liberals would argue that the market mechanism, gives individuals the freedom from any external influence to live truly free lives. They would argue that by the government taxing it's people, to pay for social welfare, they are interfering in people's lives, curtailing their financial freedom.