Four causesThe four causes or four explanations are, in Aristotelian thought, four fundamental types of answer to the question "why?", in analysis of change or movement in nature: the material, the formal, the efficient, and the final. Aristotle wrote that "we do not have knowledge of a thing until we have grasped its why, that is to say, its cause." While there are cases in which classifying a "cause" is difficult, or in which "causes" might merge, Aristotle held that his four "causes" provided an analytical scheme of general applicability.
TeleologyTeleology (from τέλος and λόγος) or finality is a reason or an explanation for something which serves as a function of its end, its purpose, or its goal, as opposed to something which serves as a function of its cause. A purpose that is imposed by human use, such as the purpose of a fork to hold food, is called extrinsic. Natural teleology, common in classical philosophy, though controversial today, contends that natural entities also have intrinsic purposes, regardless of human use or opinion.
Human natureHuman nature is a concept that denotes the fundamental dispositions and characteristics—including ways of thinking, feeling, and acting—that humans are said to have naturally. The term is often used to denote the essence of humankind, or what it 'means' to be human. This usage has proven to be controversial in that there is dispute as to whether or not such an essence actually exists. Arguments about human nature have been a central focus of philosophy for centuries and the concept continues to provoke lively philosophical debate.
Nicomachean EthicsThe Nicomachean Ethics (ˌnaɪkɒməˈkiən; ˌnɪkəməˈkiən; Ἠθικὰ Νικομάχεια, Ēthika Nikomacheia) is Aristotle's best-known work on ethics: the science of the good for human life, that which is the goal or end at which all our actions aim. It consists of ten subsections, referred to as books or scrolls, and is closely related to Aristotle's Eudemian Ethics. The work plays a pre-eminent role in explaining Aristotelian ethics. The theme of the work is a Socratic question previously explored in the works of Plato, Aristotle's friend and teacher, about how men should best live.