Socrates Socrates often credited as the founder of Western philosophy never wrote a text we mainly know about him thanks to his student Plato who wrote his teachings as dialogues he's known for the concepts of the Socratic method and Socratic irony the Socratic method takes shape in dialogue using short questions and answers in which Socrates and his interlocutors examine various aspects of an issue or an abstract meaning and find themselves at an impass completely unable to Define what they thought they understood Socrates would pretend to be ignorant of the topic under discussion to draw out the inherent nonsense in the arguments of his interlocutors this was called Socratic irony socrates's theory of virtue states that all virtues are essentially one since they are a form of knowledge for Socrates the reason a person is not good is because they lack knowledge another famous dictum No One S willingly also derives from this Theory one of socrates's most famous quotes is I know that I know nothing Plato Plato is most known for his theory of forms which denies the reality of the material world considering it only an image or copy of the real world while we may see multiple instances of different individual trees including different species these are all different imitations of the form of the tree which isn't any particular tree but rather a perfect unchanging ideal tree with all the qualities that could ever make something identifiable to us as tree is this theory is often explained using the allegory of the cave where Plato describes a group of people who have lived chained to the wall of a cave all their lives facing a blank wall the people watch Shadows projected on the wall from objects passing in front of a fire behind them and give names to these Shadows the Shadows are the prisoners reality but they are not accurate representations of the real world the Shadows represent the fragment of reality that we can normally perceive through our senses while the objects near the fire represent the true forms of objects that we can only perceive through reason Aristotle for Plato the form is separate from the actual thing it imitates for Aristotle however the form is still what phenomena are based on but is instantiated in a particular thing Plato argued that there are some forms that are not part of particular things for example it is possible that there is no particular good in existence but good is still a proper form Aristotle disagreed with Plato on this point arguing that all forms are instantiated at some point in time and that there are no forms that are unattached to existing things in addition Aristotle disagreed with Plato about the location of forms Plato spoke of the forms as existing separately from the things that participate in them while Aristotle maintained that forms exist within each thing on which each form is predicated so according to arist the form of an apple exists within each apple rather than in the world of the forms this idea is called imminent realism Aristotle also believed that the world is made out of five elements earth water fire air and ether which he believes is evenly distributed in every corner of the universe and is what the Heavenly spheres and stars are made of epicurus epicurus asserted that philosophy's purpose is to live and help others to live happy and tranquil lives seeking to remove pain or fear he thought that the biggest enemy of happiness is also the main reason humans invented philosophy the fear of death he also thought of a solution to this saying that there is no reason to fear death as when we exist death does not exist and when death exists we do not exist he thought that the entire universe consisted of two things matter and void matter is made up of atoms which are tiny bodies that have only the unchanging qualities of shape size and weight they said that in order for the universe to persist what it is ultimately made up of must not be able to be changed or else the universe would be essentially destroyed epicurus holds that there must be an infinite supply of atoms although only a finite number of types of atoms as well as an infinite amount of void because of the infinite supply of atoms there are an infinite number of Worlds epicurian believed that senses also relied on atoms every object was continually emitting particles from itself that would then interact with the Observer all Sensations such as sight smell or sound relied on these particles while the atoms that were emitted did not have the qualities that the senses were perceiving the manner in which they were emitted caused the Observer to experience those Sensations for example red particles were not themselves red but were emitted in a manner that caused the viewer to experience the color red because of epicurus's heavy Reliance on the senses he can be labeled as an empiricist Pythagoras Pythagoras was a mathematician who believed that the Universe could be explained through numbers and their relationships pythagoreans were committed to the search for abstract principles which promoted the formation and development of the ancient Greek idealist philosophy preaching the idea of the immortality of the soul and reincarnation one of the most famous contributions of pythagoreanism is the Pythagorean theorem diogenes diogenes is one of the founders of cynicism a philosophy that says that money power Fame and all other conventional desires are the wrong things to Chase and that virtue leads to true happiness according to cynicism happiness can be achieved when living in agreement with nature following one's natural sense of reason and living simply and shamelessly free from social constraints for this reason cynics live with the bare minimum needed and practice shamelessness breaking social norms diogenes himself only had a cloak a staff and a napsack he used to defecate urinate and practice self-love in public without any worry about what the public thought of him the cynics are said to have invented the idea of cosmopolitanism when he was asked where he came from diogenes replied that he was a citizen of the world I'll be making other philosophy videos subscribe to see them