The key issue of the contemporary discourse on self-deception is the necessity to explain the inner structure of consciousness or the state of mind which enable us to tell lies to ourselves or to be fooled by one’s own tricks. Two different approaches to the problem are analyzed: Sartre’s concept of bad faith as well as Davidson’s concept of self-deception. What these divergent conceptions have in common is their intentional approach. However, Sartre’s conception deriving from his ontological considerations (conceiving the consciousness in its unity) is seen as substantially different from Davidsonian rationalizing the phenomenon in question by claiming the division of mind. For Sartre a person of a bad faith is one disguising his or her freedom, i.e. the non-coincidence, which defines her or his being.