Simon Wolfe of Capsule Computers writes:
"'Cogito ergo sum', is a phrase from Descartes that I've been lucky enough to know since I was very young, which translates from Latin as 'I think, therefore I am.' While not overly useful in everyday life, knowing the phrase and its translation actually proved useful while watching Ergo Proxy as part of the phrase appears in the title, as well as the translation appearing throughout the series by some major players. Though lacking the 'sum', both 'cogito' and 'ergo' are major components of the series as a whole, that would be missed by those unfamiliar with the phrase."
