After his ever so famous "cogito ergo sum", Rene Descartes' second (deep?) thought was something like "God exists" (according to my literature). I think he brought this up mainly due to historical reasons or personal belief, but to me (although I believe in something) that's far less obvious than how he started out.
Why didn't he at least continue with something like "there exist impressions, that fed my mind, such that I can doubt their existence, because I think they are created by putative evil demons" or "there exist senses, that fed my mind with data, be it right or wrong"?
To me, these two expressions are as clear as the first one. Am I right and are there other simple truths?