Rationality is a multidimensional concept. In section 1.5, it was mentioned that the growth-of-knowledge (GK) theory of entrepreneurship is limited to the cognitive-logical dimension of inquiry and that it does not include other important dimensions within its ambit. It aims to explore the hidden structure of rationality which underlies entrepreneurial activity. It must be emphasised that the entire entrepreneurial learning methodology that is developed in the following chapters (i.e. the methodological rules of the falsificationist entrepreneur) constitutes the GK conception of entrepreneurial rationality. This chapter is restricted to only a few general comments on the rationality of the entrepreneur. GK (or non-justificationist) rationality can be succinctly described as consisting in the disposition to learn from mistakes. The GK theory of entrepreneurship assumes that entrepreneurs are rational in this sense: at least some entrepreneurs are presumed to proceed by the critical method of trial and the elimination of error. It is predicted that entrepreneurs who adopt GK rationality are more successful than entrepreneurs who do not (see sections 6.1 and 10.1). But the new theory does not claim that (successful) entrepreneurs always adopt critical and rational policies with respect to their own ideas.