I describe action theory as a particularly well fitting theory for entrepreneurship because entrepreneurship depends to a high degree on Personal Initiative defined as being self-starting, future oriented and overcoming barriers. The concepts of goals, environmental mapping in active mental models, plans, and active feedback processing are developed and empirical literature supporting such a theoretical model is described. I compare this theory with two other theories of action ((McMullen & Shepherd, 2006; Sarasvathy, 2001), to ask how these different theories are different and can learn from each other.