L.E.’s Reviews > Existentialism is a Humanism > Status Update

Been racking my brain but I still can't understand how his statement that 'we cannot decide a priori what it is that should be done' holds up to his statements after. E.g., there is the thesis of man making himself 'in relation to his commitments' but in certain cases, isn't there an awareness prior said commitments, not matter how misled?