Ontology work of Tony Fry is important. René Descartes, with "je pense donc je suis" or "cogito ergo sum" or "I think, therefore I am", argued that "the self" is something that we can know exists with epistemological certainty. Descartes argued further that this knowledge could lead to a proof of the certainty of the existence of God, using the ontological argument that had been formulated first by Anselm of Canterbury. Certainty about the existence of "the self" and "the other", however, came under increasing criticism in the 20th century. Sociological theorists, most notably George Herbert Mead and Erving Goffman, saw
Cogito (software) on a Cogito managed repository. Conversely, most Cogito commands can be used on repositories primarily managed by Git or StGIT. Cogito is implemented as a set of Bash scripts (unlike Git, which is written mostly in C and portable Unix shell). As of April 2007 the project is stalled and declared "for sale", because a lot of the functionality has already been taken over by git, and the maintainer, Petr Baudiš, decided it would be better to focus on improving git-core. Cogito is released under the GNU GPL. As of May 2008, Cogito does not work well with recent Git