 The text of the Logic is organized around the four mental operations important to the “art of thinking”: conceiving ideas, affirming and denying propositions (judging), affirming and denying propositions on the basis of other propositions (reasoning, i.e., inferring), and ordering results of good reasoning. Logic is the sequential application of these operations. Conceiving ideas is the “first action” of the mind, propositions are formed from ideas, and reasoning involves propositions. Ordering these products of thought constitutes method. This organization reflects the point that logic is taken to be primarily a science of the activity of thinking in the pursuit of knowledge. This framework for understanding logic is now regarded as “psychologistic” in opposition to both earlier and post-Fregean approaches that focus on methods for dealing with formal aspects of reasoning.