Book excerpt: This book is a condensation of a large body of work concerning human learning carried out over a period of more than five years by Dr. Sun and his collaborators. In a nutshell, this work is concerned with a broad framework for studying human cognition based on a new approach that is characterized by its focus on the dichotomy of, and the interaction between, explicit and implicit cognition and a computational model that implements this framework. In this work, a broad, generic computational model was developed that instantiates Dr. Sun's framework and enables the testing of his theoretical approach in a variety of ways. With this model, simulation results were matched with data of human cognition in a variety of different domains. Formal (mathematical and computational) analyses were also carried out to further explore the model and its numerous implementational details. Furthermore, this book addresses some of the most significant theoretical issues, such as symbol grounding, intentionality, social cognition, consciousness, and other theoretical issues in relation to the framework. The general framework and the model developed generate interesting insights into these theoretical issues.