Bion left us an important technical principle. We can summarize it in the concepts of negative capacity and faith. They are two sides of the same coin, but they are also widely misunderstood. It is not easy to accept the idea that the analyst must listen to the patient by actively depriving himself of memory, desire, and understanding; not only, but that the analyst has also to focus on the here and now and radically put concrete and historical reality in parentheses. What does it mean for the analyst that the only real world is psychic reality? Why is it so important to favor the “oscillating” work of dream and imagination? The author discusses these concepts, relates them to Freud's concept of evenly suspended or free-floating attention and to the concept of empathy. Finally, he gives some clinical vignettes showing these principles have been reinvented in the post-Bionian field theory.