The Simple, the Complex, the Meaningful, and the Beautiful.

J. Barkley Rosser Jr. dedicated his career to the study of complexity and nonlinear dynamics applied to economic matters. From his extensive work, four ideas stand out: (a) relevant economic processes can be expressed under the form of relatively simple modelling apparatus; (b) low-dimensional nonlinear systems often involve complex patterns of evolution; (c) the identified nonlinearities have significant economic meaning, and (d) there is an inherent aesthetic beauty underlying the corresponding mathematical results. This article is composed by two blocks. In the first part, the work by J. Barkley Rosser Jr. is surveyed, with a special emphasis placed on the four above-mentioned items. In the second part, a two-equation discrete-time model of diffusion of ideas is proposed and subject to analytical and graphical treatment, with the objective of illustrating how a simple dynamic model may generate complex and visually attractive dynamics with economic meaning.