Schön's concept of "reflection in action", particularly when interpreted from a sociocultural perspective, is often used as frame with which to consider the relationship between theoretical and tacit knowledge in the work of teachers. This paper presents an alternative interpretative frame for Schön which makes use of the ideas of Wilfred Bion, perhaps the most influential psychoanalyst of the second half of the twentieth century. It is argued that it is the productive emotional struggle with uncertainty that lies within Schön's moment, which ultimately leads to the teacher coming to a moment of decision about what the child might need in a particular situation. This (contingent) understanding arises from a dialectic intertwining of knowledge derived from intersubjective relationship and theoretical knowledge, for example, about typical and atypical development in children. Implications for professional practice particularly in relation to working with children with special educational needs are discussed.