Mill sees experience as the exclusive and sole source of knowledge. He rejects the idea of what he calls intuitive knowledge, which could apply to any kind of knowledge that the mind grasps immediately and with certainty rather than verifying through observation over a period of time. Intuitive knowledge would include such things as Plato’s Forms or Descartes’ “I think, therefore I am.” However, if the mind cannot intuitively perceive itself as a self, the question arises, what does the self consists of?

Mill imagines the body as a permanent potentiality of sensations and the mind as a series of actual and possible states of being. In other words, neither the brain nor the body can be said to be a “person,” in the sense we normally use that word, meaning a stable, consistent, identifiable self. Mill grapples with the problem of how a series of different states or impressions can be aware of itself. Mill observes that a bond seems to exist between the various parts of a series (such as the different states of mind through which a person goes), which allows us to say that these parts are the feelings of a person, who is the same person throughout. This bond constitutes the ego. However, Mill’s argument here seems to depend on the existence of a faculty of perception very much like intuition—our minds apparently intuit the bond between elements in a series.

Popular pages: Selected Works of John Stuart Mill