A mind without reflective self-awareness is what I call an "immature mind". There are several reasons why I find studying the immature mind rewarding. First, it brings philosophy into connection with empirical work in developmental psychology, since infants and young children are prime examples of immature minds. Secondly, much of our decisions are based not on considered judgments but on crude heuristics that operate without self-reflection. And thirdly, studying the immature mind may help to overcome various problematic dichotomies: the dichotomy between behaviorism and mentalism, between cognitive and meta-cognitive functioning, and between conceptual and non-conceptual content. An additional reason for me to start working on immature mental processes was the fact that I had the great opportunity of collaborating closely with Josef Perner and his team at the Department of Psychology, which I have done for many years now.