Aristotle

Propositions are the meanings of declarative sentences, objects of beliefs, and bearers of truth values. They explain how different sentences, like the English "Snow is white" and the German "Schnee ist weiß", can have identical meaning by expressing the same proposition. Similarly, they ground the fact that different people can share a belief by being directed at the same content. True propositions describe the world as it is, while false ones fail to do so. Researchers distinguish types of propositions by their informational content and mode of assertion, such as the contrasts between affirmative and negative propositions, between universal and existential propositions, and between categorical and conditional propositions.

Many theories of the nature and roles of propositions have been proposed. Realists argue that propositions form part of reality, a view rejected by anti-realists. Non-reductive realists understand propositions as a unique kind of entity, whereas reductive realists analyze them in terms of other entities. One proposal sees them as sets of possible worlds, reflecting the idea that understanding a proposition involves grasping the circumstances under which it would be true. A different suggestion focuses on the individuals and concepts to which a proposition refers, defining propositions as structured entities composed of these constituents. Other accounts characterize propositions as specific kinds of properties, relations, or states of affairs. Philosophers also debate whether propositions are abstract objects outside space and time, psychological entities dependent on mental activity, or linguistic entities grounded in language. Paradoxes challenge the different theories of propositions, such as the liar's paradox. The study of propositions has its roots in ancient philosophy, with influential contributions from Aristotle and the Stoics, and later from William of Ockham, Gottlob Frege, and Bertrand Russell.

In biology, adaptation has three related meanings. Firstly, it is the dynamic evolutionary process of natural selection that fits organisms to their environment, enhancing their evolutionary fitness. Secondly, it is a state reached by the population during that process. Thirdly, it is a phenotypic trait or adaptive trait, with a functional role in each individual organism, that is maintained and has evolved through natural selection.

Historically, adaptation has been described from the time of the ancient Greek philosophers such as Empedocles and Aristotle. In 18th and 19th-century natural theology, adaptation was taken as evidence for the existence of a deity. Charles Darwin and Alfred Russel Wallace proposed instead that it was explained by natural selection.

Zoology (/zoʊˈɒlədʒi/ zoh-OL-ə-jee, UK also /zuˈ-/ zoo-) is the scientific study of animals. Its studies include the structure, embryology, classification, habits, and distribution of all animals, both living and extinct, and how they interact with their ecosystems. Zoology is one of the primary branches of biology. The term is derived from Ancient Greek ζῷον, zōion ('animal'), and λόγος, logos ('knowledge', 'study').

Although humans have always been interested in the natural history of the animals they saw around them, and used this knowledge to domesticate certain species, the formal study of zoology can be said to have originated with Aristotle. He viewed animals as living organisms, studied their structure and development, and considered their adaptations to their surroundings and the function of their parts. Modern zoology has its origins during the Renaissance and early modern period, with Carl Linnaeus, Antonie van Leeuwenhoek, Robert Hooke, Charles Darwin, Gregor Mendel and many others.

Substance 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. They can be described in terms of a persisting substance gaining or losing properties. Attributes or properties, on the other hand, are entities that can be exemplified by substances. Properties characterize their bearers; they express what their bearer is like.

Substance is a key concept in ontology, the latter in turn part of metaphysics, which may be classified into monist, dualist, or pluralist varieties according to how many substances or individuals are said to populate, furnish, or exist in the world. According to monistic views, there is only one substance. Stoicism and Spinoza, for example, hold monistic views, that pneuma or God, respectively, is the one substance in the world. These modes of thinking are sometimes associated with the idea of immanence. Dualism sees the world as being composed of two fundamental substances (for example, the Cartesian substance dualism of mind and matter). Pluralist philosophies include Plato's Theory of Forms and Aristotle's hylomorphic categories.

Narratology is the study of narrative and narrative structure and the ways that these affect human perception. The term is an anglicisation of French narratologie, coined by Tzvetan Todorov (Grammaire du Décaméron, 1969). Its theoretical lineage is traceable to Aristotle (Poetics) but modern narratology is agreed to have begun with the Russian formalists, particularly Vladimir Propp (Morphology of the Folktale, 1928), and Mikhail Bakhtin's theories of heteroglossia, dialogism, and the chronotope first presented in The Dialogic Imagination (1975).

Cognitive narratology is a more recent development that allows for a broader understanding of narrative. Rather than focus on the structure of the story, cognitive narratology asks "how humans make sense of stories" and "how humans use stories as sense-making instruments".

The soul is the purported immaterial aspect or essence of a living being. It is typically believed to be immortal and to exist apart from the material world. The three main theories that describe the relationship between the soul and the body are interactionism, parallelism, and epiphenomenalism. Anthropologists and psychologists have found that most humans are naturally inclined to believe in the existence of the soul and that they have interculturally distinguished between souls and bodies.

The soul has been the central area of interest in philosophy since ancient times. Socrates envisioned the soul to possess a rational faculty, its practice being man's most godlike activity. Plato believed the soul to be the person's real self, an immaterial and immortal dweller of our lives that continues and thinks even after death. Aristotle sketched out the soul as the "first actuality" of a naturally organized body—form and matter arrangement allowing natural beings to aspire to full actualization.

Eudaimonia (also spelled eudaemonia)(/juːdɪˈmoʊniə/; Ancient Greek: εὐδαιμονία [eu̯dai̯moníaː]) is a Greek word literally translating to the state or condition of good spirit, and which is commonly translated as happiness or welfare.

In the works of Aristotle, eudaimonia was the term for the highest human good in older Greek tradition. It is the aim of practical philosophy-prudence, including ethics and political philosophy, to consider and experience what this state really is and how it can be achieved. It is thus a central concept in Aristotelian ethics and subsequent Hellenistic philosophy, along with the terms aretē (most often translated as virtue or excellence) and phronesis ('practical or ethical wisdom').

Geocentrism is a superseded astronomical model description of the Universe with Earth at the center. It is also known as the geocentric model, often exemplified specifically by the Ptolemaic system. Under most geocentric models, the Sun, the Moon, stars, and planets all orbit Earth. The geocentric model was the predominant description of the cosmos in many European ancient civilizations, such as those of Aristotle in Classical Greece and Ptolemy in Roman Egypt, as well as during the Islamic Golden Age.

Two observations supported the idea that Earth was the center of the Universe. First, from anywhere on Earth, the Sun appears to revolve around Earth once per day. While the Moon and the planets have their own motions, they also appear to revolve around Earth about once per day. The stars appeared to be fixed on a celestial sphere rotating once each day about an axis through the geographical poles of Earth. Second, Earth seems to be unmoving from the perspective of an earthbound observer; it feels solid, stable, and stationary.

Macedonia (/ˌmæsɪˈdoʊniə/ MASS-ih-DOH-nee-ə; Greek: Μακεδονία, Makedonía), also called Macedon (/ˈmæsɪdɒn/ MASS-ih-don), was an ancient kingdom on the periphery of Archaic and Classical Greece, which later became the dominant state of Hellenistic Greece. The kingdom was founded and initially ruled by the royal Argead dynasty, which was followed by the Antipatrid and Antigonid dynasties. Home to the ancient Macedonians, the earliest kingdom was centred on the northeastern part of the Greek peninsula, and bordered by Epirus to the southwest, Illyria to the northwest, Paeonia to the north, Thrace to the east and Thessaly to the south.

Before the 4th century BC, Macedonia was a small kingdom with its capital at Aigai, outside of the area dominated by the great city-states of Athens, Sparta and Thebes, and briefly subordinate to the Achaemenid Empire. During the reign of the Argead king Philip II (359–336 BC), Macedonia (with its capital at Pella) subdued mainland Greece and the Thracian Odrysian kingdom through conquest and diplomacy. With a reformed army containing phalanxes wielding the sarissa pike, Philip II defeated the old powers of Athens and Thebes in the Battle of Chaeronea in 338 BC. Philip II's son Alexander the Great, leading a federation of Greek states, accomplished his father's objective of commanding the whole of Greece when he destroyed Thebes after the city revolted. During Alexander's subsequent campaign of conquest, he overthrew the Achaemenid Empire and conquered territory that stretched as far as the Indus River. For a brief period, his Macedonian Empire was the most powerful in the world – the definitive Hellenistic state, inaugurating the transition to a new period of Ancient Greek civilization. Greek arts and literature flourished in the new conquered lands and advances in philosophy, engineering, and science spread across the empire and beyond. Of particular importance were the contributions of Aristotle, tutor to Alexander, whose writings became a keystone of Western philosophy.