I expect that this chapter will be the most challenging for readers with limited prior knowledge of adult developmental psychology. It has certainly been the most challenging to write—largely because there is so much material on higher stages of reasoning, yet so little coherence of it to date. In this chapter we explore a range of adult development theories created by psychologists who saw beyond the limits of Piaget's cognitive model. I introduce the main researchers who have identified and described postformal reasoning qualities and reiterate the shift from formal to postformal reasoning. The postformal reasoning features they identify are listed, and from these I theorise and discuss twelve distinct postformal reasoning qualities. By the end you will have a coherent picture of how postformal reasoning is conceptually aligned with four themes distilled from the evolution of consciousness research.