Modern philosophyModern philosophy is philosophy developed in the modern era and associated with modernity. It is not a specific doctrine or school (and thus should not be confused with Modernism), although there are certain assumptions common to much of it, which helps to distinguish it from earlier philosophy. The 17th and early 20th centuries roughly mark the beginning and the end of modern philosophy. How much of the Renaissance should be included is a matter for dispute; likewise modernity may or may not have ended in the twentieth century and been replaced by postmodernity.
Practical reasonIn philosophy, practical reason is the use of reason to decide how to act. It contrasts with theoretical reason, often called speculative reason, the use of reason to decide what to follow. For example, agents use practical reason to decide whether to build a telescope, but theoretical reason to decide which of two theories of light and optics is the best. Practical reason is understood by most philosophers as determining a plan of action. Thomistic ethics defines the first principle of practical reason as "good is to be done and pursued, and evil is to be avoided.
Principle of sufficient reasonThe principle of sufficient reason states that everything must have a reason or a cause. The principle was articulated and made prominent by Gottfried Wilhelm Leibniz, with many antecedents, and was further used and developed by Arthur Schopenhauer and Sir William Hamilton, 9th Baronet. The modern formulation of the principle is usually ascribed to early Enlightenment philosopher Gottfried Leibniz. Leibniz formulated it, but was not an originator.
Law of thoughtThe laws of thought are fundamental axiomatic rules upon which rational discourse itself is often considered to be based. The formulation and clarification of such rules have a long tradition in the history of philosophy and logic. Generally they are taken as laws that guide and underlie everyone's thinking, thoughts, expressions, discussions, etc. However, such classical ideas are often questioned or rejected in more recent developments, such as intuitionistic logic, dialetheism and fuzzy logic.
History of economic thoughtThe history of economic thought is the study of the philosophies of the different thinkers and theories in the subjects that later became political economy and economics, from the ancient world to the present day in the 21st century. This field encompasses many disparate schools of economic thought. Ancient Greek writers such as the philosopher Aristotle examined ideas about the art of wealth acquisition, and questioned whether property is best left in private or public hands.
