PhilosophyPhilosophy (love of wisdom in ancient Greek) is a systematic study of general and fundamental questions concerning topics like existence, reason, knowledge, values, mind, and language. It is a rational and critical inquiry that reflects on its own methods and assumptions. Historically, many of the individual sciences, like physics and psychology, formed part of philosophy. But they are considered separate academic disciplines in the modern sense of the term.
OusiaOusia (ˈuːziə,_ˈuːsiə,_ˈuːʒə,_ˈuːʃə; οὐσία) is a philosophical and theological term, originally used in ancient Greek philosophy, then later in Christian theology. It was used by various ancient Greek philosophers, like Plato and Aristotle, as a primary designation for philosophical concepts of essence or substance. In contemporary philosophy, it is analogous to English concepts of being and ontic. In Christian theology, the concept of θεία ουσία (divine essence) is one of the most important doctrinal concepts, central to the development of trinitarian doctrine.
StoicismStoicism is one of the four major schools of thought established in the Hellenistic period. It was founded in the ancient Agora of Athens by Zeno of Citium around 300 BC. The Stoics believed that the practice of virtue is enough to achieve eudaimonia: a well-lived, flourishing life. The Stoics identified the path to achieving it with a life spent practicing certain virtues in everyday life such as courage or temperance and living in accordance with nature.
Potentiality and actualityIn philosophy, potentiality and actuality are a pair of closely connected principles which Aristotle used to analyze motion, causality, ethics, and physiology in his Physics, Metaphysics, Nicomachean Ethics, and De Anima. The concept of potentiality, in this context, generally refers to any "possibility" that a thing can be said to have. Aristotle did not consider all possibilities the same, and emphasized the importance of those that become real of their own accord when conditions are right and nothing stops them.
Substance theorySubstance theory, or substance–attribute theory, is an ontological theory positing that objects are constituted each by a substance and properties borne by the substance but distinct from it. In this role, a substance can be referred to as a substratum or a thing-in-itself. Substances are particulars that are ontologically independent: they are able to exist all by themselves. Another defining feature often attributed to substances is their ability to undergo changes. Changes involve something existing before, during and after the change.