Subjectivism given consciousness is dependent on that consciousness. This has its philosophical basis in the writings of Descartes (see "cogito ergo sum"), and forms a cornerstone of Søren Kierkegaard's philosophy. Recently, more modest versions of metaphysical subjectivism have been explored. For example, I might hold that it is a "fact" that chocolate is tasty, even though I recognize that it is not tasty to everyone. This would imply that there are facts that are "subjective". (Analogously, one might hold that it is a fact that it is winter in the Northern Hemisphere, even though this is not always the case, implying
Cogito, ergo sum for thought". In other words, "the only claim that is indubitable here is the agent-independent claim that there is cognitive activity present". The objection, as presented by Georg Lichtenberg, is that rather than supposing an entity that is thinking, Descartes should have said: "thinking is occurring." That is, whatever the force of the "cogito", Descartes draws too much from it; the existence of a thinking thing, the reference of the "I," is more than the "cogito" can justify. Friedrich Nietzsche criticized the phrase in that it presupposes that there is an "I", that there is such an activity as "thinking",