This chapter reviews the fundamental aspects of psychoanalysis which is the search for meaning and describes a major problem with that search that takes place under uncertainty. The tool for carrying out this search is therapeutic discourse and it encompasses both conscious and unconscious elements. The chapter discusses the clinical judgments undertaken under conditions of uncertainty that is probably of even more importance in the therapeutic situation which helps to better understand how to reach conclusion about the patients and how to decide what to do/not to do. Heuristics, the shortcuts are a necessary and often helpful part of our thinking; one can learn to distinguish how the heuristics facilitate the therapeutic process or distort it. Although heuristics can function as quite reasonable estimation procedures, their use is sometimes confounded by individual patterns of biases in the way one collects information. Recent studies in clinical medicine shows that clinicians too often rely on the representativeness and availability heuristics.