In this lecture, a survey of some theoretical progresses on several basic problems in systems and control science will be presented. We will begin by discussing the following two problems that are related to the emergence of complex systems: When flocks with large population will be synchronized? Can a general theory for distributed adaptive filtering be established? Then we will focus on the understanding of the feedback mechanism for regulating uncertain dynamical systems and to answer the following questions: What are the main features of adaptive control systems where online estimators are combined with real-time controllers in the same feedback loop? Can we establish the global stability and optimality of the well-known self-tuning regulators? What is the rationale behind the widespread use of the classical proportional-integral-derivative (PID) control? How about the maximum capability and fundamental limitations of the feedback mechanism in dealing with nonlinear uncertain systems? Finally, we will discuss how a theory may be established for game-based control systems, where some “intelligent” behaviors including dynamical games may exist in the systems to be regulated.