While the consideration of functional and technical criteria, as well as a sense of coherence are basic requirements for solving a design problem; it is the ability to induce an intended quality of aesthetic experience that is the hallmark of design expertise. Expert designers possess a highly developed sense of design, or what in this research is called aesthesis. Reflection on 25 years teaching design in the USA, Hungary, and China led to the observation that most successful design students, more than intellectual ability, drawing, model making or drive, all seemed to possess what may be called an intuitive sense of good design. It is not that they already know how to design, or that they are natural designers, it is that they have a more developed sense aesthesis. This research takes a multi-disciplinary approach to build a theory that describes what is involved in acquiring design expertise,identifies how aesthesis functions in the design process, and determines if what appears to be an intuitive sense of design is just natural talent or an acquired ability.