Overview
The word liberty can refer to many things, but Isaiah Berlin recognized two main types of liberty. Berlin described a statement such as "I am slave to no man" as one of Negative Liberty, that is, freedom from another individual's direct interference. He contrasted this with a Positive Freedom statement such as "I am my own master", which lays claim to a freedom to choose one's own pursuits in life.
Charles Taylor's clarification may be even more useful. Taylor explains that Negative Freedom is an "opportunity-concept": one possesses Negative Freedom if one is not enslaved by external forces, and has equal access to a society's resources (regardless of how one decides to spend their time). Positive Freedom, says Taylor, is an "exercise-concept": possessing it might mean that one is not internally constrained; one must be able to act according to their highest self - according to reason. Suppose a rich and powerful actor is also a drug addict. This actor may possess a great deal of Negative Liberty, but very little Positive Liberty according to Taylor. Recall that, by Taylor's definitions, Positive Freedom entails being in a mature state of decision making, free of internal restraints (e.g. weakness, fear, ignorance, etc.).
Read more about this topic: Positive Liberty