 Da Silva Filho obtained his B.A. in philosophy from the Universidade Estadual de Santa Cruz and his M.A. and Ph.D. in communication and contemporary culture from the Universidade Federal da Bahia (UFBA). Currently a professor at UFBA, he works in the fields of philosophy of mind and epistemology. In some of his publications, he has examined certain skeptical difficulties concerning self-knowledge (da Silva Filho 2007, 2008). Even though he was not one of Porchat’s students, he has also been influenced by Porchat’s skeptical stance.