I personally feel that "Cogito ergo sum" means that taking assertions on faith is simply foolhardy, because the only opinion that one can truly trust is your own. Not that you should take my word for it.
at·ten·tion deficit disorder (-tnshn)
n. Abbr. ADD
A syndrome, usually diagnosed in childhood, characterized by a persistent pattern of impulsiveness, a short attention span, and sometimes hyperactivity, and interfering especially with academic, occupational, and social performance.
Just google his name and "rivets". Looks like it's actually a joking remark Card makes himself to express what it's like to dabble in both sci-fi and fantasy (Card is successful with both).
Card maintains that switching genres wasn't a difficult
thing for him. He believes that, ultimately, the
difference between the two genres is largely on the
surface. "Half joking, I was writing to Ben (Bova) about
this very subject, and I said, look, fantasy has trees,
and science fiction has rivets. That's it, that's all
the difference there is, the difference of feel,
perception.