This paper contrasts the modern use of the assumption that rationality as reflected in simple models of utility and profit maximization guides individual economic behaviour to literature both between 1890 and 1930 which sharply challenged the use of such an assumption and later literature in economic psychology from Herbert Simon onwards which sees economic (and other) cognitive processes in different ways. Some of the earlier literature proposed objective and operational notions of rationality based on the availability of information, ability to reason (cognitive skills), and even morality. Learning played a major role in individuals achieving what was referred to as complete rationality. I draw on these ideas, and suggest that developi...