Art and science are fundamental building blocks of human knowledge. Science is objective and structured. Art is subjective and expressive. In this thesis, we ask the question, "Could there be a logical side to Art?" Perhaps there exist fundamental elements or building blocks in Art that can be exploited and used in a parametric model? For the purposes of our research, we limit the discussion of Art to paintings and sketches. We examine art and art style discovery as a form of Non-photorealistic rendering (NPR). We designed a flock based brush model as the core mechanism for art style rendering. We used a stroke-based, evolutionary approach to NPR in the form of an Interactive Genetic Algorithm (IGA). By using our nature inspired brush model and IGA driven art style discovery prototype, we have re-created existing styles such as Impressionist, Sketch and Pointillism. Our system also serves as a platform to facilitate interactive art style discovery by way of an evolutionary process.