F.A. Hayek, The Road to Serfdom

The question whether the state should or should not "act" or "interfere" poses an altogether false alternative, and the term "laissez faire" is a highly ambiguous and misleading description of the principles on which a liberal policy is base. Of course, every state must act and every action of the state interferes with something or other. But that is not the point. The important question is whether the individual can foresee the action of the state and make use of this knowledge as a datum in forming his own plans, with the result that the state cannot control the use made of its machinery and that the individual knows precisely how far he will be protected against interference from others, or whether the state is in a position to frustrate individual efforts. The state controlling weights and measures (or preventing fraud and deception in any other way) is certainly acting, while the state permitting the use of violence, for example, by strike pickets, is inactive. Yet it is in the first case that the state observes liberal principles and in the second that it does not.

[Chapter Six: Planning and the Rule of Law]