Agency (sociology) experiences, and the perceptions held by the society and the individual, of the structures and circumstances of the environment one is in and the position they are born into. Disagreement on the extent of one's agency often causes conflict between parties, e.g. parents and children. The concept of agency has existed since the Enlightenment. René Descartes' phrase Cogito ergo sum stated that anyone who could think is an agent , and any agent capable of knowing that it can think was a subject. Immanuel Kant expanded on this theory by stating that the only way to truly become self-aware is
Cogito, ergo sum in the former case, and an objective thinker in the latter. He argues, first, that it is impossible to make sense of "there is thinking" without relativizing it to "something." However, this something cannot be Cartesian egos, because it is impossible to differentiate objectively between things just on the basis of the pure content of consciousness. The obvious problem is that, through introspection, or our experience of consciousness, we have no way of moving to conclude the existence of any third-personal fact, to conceive of which would require something above and beyond just the purely subjective contents of the mind.