Short answers, pulled from the story.
Andronicus of Rhodes coined the term metaphysics in the first century BCE. He organized Aristotle's scattered treatises and titled the collection Metaphysics two centuries after Aristotle's death. The Greek term literally means after the physics, indicating that these texts were to be studied after Aristotle's works on natural science.
Realists argue that universals are real, mind-independent entities that exist in addition to particulars. Nominalists reject the idea that universals exist in either form, claiming the world is composed exclusively of particulars. Conceptualists offer an intermediate position, stating that universals exist, but only as concepts in the mind used to order experience by classifying entities.
According to the A-series theory, the flow of time is real, meaning that events are categorized into the past, present, and future. From the perspective of the B-series theory, time is static, and events are ordered by the temporal relations earlier-than and later-than without any essential difference between past, present, and future. Eternalism holds that past, present, and future are equally real, whereas presentism asserts that only entities in the present exist.
A key aspect of the mind-body problem is the hard problem of consciousness or how to explain that physical systems like brains can produce phenomenal consciousness. According to Cartesian dualism, minds and bodies are distinct substances that causally interact with each other in various ways but can, at least in principle, exist on their own. Materialists state that all reality is at its core material and explain mind in terms of certain aspects of matter, such as brain states, behavioral dispositions, or functional roles.
In ancient India, starting in the 7th century BCE, the Upanishads were written as religious and philosophical texts that examine how ultimate reality constitutes the ground of all being. They further explore the nature of the self and how it can reach liberation by understanding ultimate reality. This period also saw the emergence of Buddhism in the 6th century BCE, which denies the existence of an independent self and understands the world as a cyclic process.