Short answers, pulled from the story.
Thales of Miletus started Western philosophy in the 6th century BCE by declaring that water was the fundamental substance of all things. This statement marked the beginning of Western philosophy, shifting the explanation of the cosmos from the whims of gods to rational inquiry.
Socrates lived from 469 to 399 BCE and transformed the focus of inquiry from the nature of the cosmos to the nature of the human soul and the question of how to lead a good life. He used Socratic dialogues to explore topics and critically reflect on underlying ideas, prompting his audience to recognize their own ignorance.
The medieval period in Western philosophy spanned from 400 to 500 CE to 1400 or 1500 CE and was defined by its intense focus on religious thought and the relationship between reason and faith. Intellectual activity became concentrated within the Church following the closure of Plato's Academy by the Byzantine Emperor Justinian I in 529 CE.
The Renaissance period began in the mid-14th century and lasted until the early 17th century, marking a significant departure from the medieval focus on religious and scholastic traditions. This movement originated in Italy and spread across Western Europe, characterized by a renewed interest in Ancient Greek philosophy and the emergence of humanism.
Early modern philosophy encompassing the 17th and 18th centuries was defined by the emergence of empiricism and rationalism, two schools of thought that shared a common goal of establishing a clear, rigorous, and systematic method of inquiry. John Locke argued that all knowledge is derived from experience, while René Descartes employed methodological doubt to find an indubitable foundation for knowledge.