This chapter begins with the claim that current predominant approaches to thinking in educational theory and policy are grounded in certain philosophical assumptions about the nature of thinking and the human being who thinks. I characterise such assumptions as ‘rationalistic’ to exemplify their relation with formalisable, mechanistic ways of thinking, and with an intellectualised, disengaged picture of the human being who thinks. I critique such a conception on the grounds that it closes down the possibilities of thinking in education, cramping thought into the narrow straits of reason. Yet alternative conceptions of thinking, I argue, can be found within the philosophical schools of phenomenology, ordinary language philosophy and post-structuralism. I explore the connections and contrasts between key thinkers in these traditions to work towards establishing a more adequate philosophical account of human thinking. At the end of the chapter, I suggest how the teaching of thinking in schools might consequently be reconceived, in ways that are richer and more robust than rationalism.