Aristotle argued that the state is a natural institution rather than a product of convention or force. He believed that humans are 'political animals' by nature, and the state is the final stage of social evolution, beginning with the family and the village. Because humans have an innate drive to live in a community to achieve the 'good life,' the state is seen as a natural necessity.

In 'The Poetics', Aristotle provides a systematic analysis of the art of poetry, with a primary focus on tragedy. He defines tragedy as an imitation of an action that is serious and complete, and he explores how it achieves catharsis, or the purgation of emotions like pity and fear.

The term 'city-state' (polis) refers to the independent political units of ancient Greece, such as Athens and Sparta. These entities functioned as sovereign states, encompassing a central city and its surrounding territory, where citizens directly participated in governance and public life, distinct from modern nation-states.

Aristotle, in his seminal work 'Politics,' defines the citizen not by residence or legal rights alone, but by the active capacity to share in the deliberative and judicial functions of the polis. This definition emphasizes active political participation as the hallmark of citizenship.

For Aristotle, psychology (derived from 'psyche', meaning soul) is the study of the soul, which he defined as the 'form' or the organizing principle of a living body. He argued that the soul is inseparable from the body in living beings, and its study involves understanding the capacities and functions that distinguish living things from non-living matter.

Aristotle did not write a specific work titled 'Psychology'. While he explored the nature of the soul and living beings in his treatise 'De Anima' (On the Soul), 'Psychology' as a distinct academic discipline or book title is a modern invention. His biological and philosophical inquiries often touched upon what we now call psychology, but he categorized these under the study of life and the soul.

Aristotle posits the Unmoved Mover as the primary cause of all motion in the universe. Because it is the source of all change while remaining unchanged itself, it must be eternal, immaterial, and pure actuality. It does not intervene in human affairs or possess human-like moral qualities, as its nature is purely intellectual and self-contemplative.

Aristotle, in his seminal work 'Politics', viewed the constitution (politeia) as the fundamental organization of the state. He argued that the constitution determines the distribution of offices, the sovereign power, and the way of life of the citizens. By defining the state through the arrangement of its citizens, Aristotle emphasized that the constitution is essentially the structure of the political community itself.

The followers of Aristotle were known as the Peripatetics, a name derived from the Greek word 'peripatetikos,' meaning 'given to walking about.' This term refers to Aristotle's well-documented habit of walking through the Lyceum's grounds while lecturing and discussing philosophical matters with his students, rather than remaining seated in a formal classroom setting.

Aristotle explores the concept of 'akrasia' or incontinence, which is the failure to act according to one's knowledge of the good. The tension in ethical decision-making lies in the struggle between reason and the passions. Continence (enkrateia) is the virtue of mastering one's desires through reason, representing the central struggle for the moral agent in Aristotelian ethics.