The nature of the knowledge base in empathy is explored. The presumption is that empathic responses are active in both analyst and analysand. The variety of meanings of empathic experience is reviewed and aspects of its implementation discussed. Reservations regarding the accuracy, certainty, and limitations of empathy are considered. The subsequent analysis focuses on empathic affective attunement. The role of underlying mechanisms, both neurophysiological-nonconscious and psychological-unconscious, are explored. An attempt is made to integrate contributory functions of these processes in a provisional model of empathic attunement and its differentiation from countertransference responses in the analyst.