Xenophanes of Colophon (Zuh-nah-fuh-neez, c. 560—480 BCE) was a Greek philosopher, poet, and critic whose views survive only as fragments, the traditional term for quotations attributed to the earliest Greek philosphers by later Greek and Roman philosophers.  His work criticized and satirized a wide range of ideas current in his society, including the ordinary Greek’s belief in a pantheon of anthropomorphic gods.  Xenophanes rejected the idea that the gods resembled humans in form, motives, and thought.  In one of his more famous fragments, Xenophanes is supposed to have said that if oxen were capable of imagining the gods, they would imagine them in the form of oxen.  Instead, Xenophanes argued that there is but “one god greatest among gods and men,” who is universal, unchanging, immobile, and always present and whose form, rather than being human, is identical with the universe itself.  This view classes him as one of first monotheists of the Western world.
Heraclitus of Ephesus (hair-uh-kly-tus, c. 540-475 BCE) was born in Ephesus, a cosmopolitan Ionian city along the western coast of Anatolia (modern Turkey).  He is typically described by later biographers as a misanthrope who heaped scorn on his fellow citizens, eventually withdrawing from society into the mountains outside Ephesus, where he lived as a hermit, eating grasses and plants.  Heraclitus reputedly advocated sobriety and meditative reflection because one must attain deep self-knowledge before he or she can understand rightly what sensory data reveal about the nature of the kosmos.  Heraclitus’s fragments refer to the “Logos” and flatly declare that “men always prove to be uncomprehending [of it], both before they have heard it and when once they have heard it.” The Ephesian philosopher urges his readers to listen “not to me but to the Logos it is wise to agree that all things are one,” thus positioning himself more as an oracle than as a philosopher propounding a rational framework for comprehending the universe.  The precise nature of Heraclitus’ Logos is difficult to pin down.  As G.S. Kirk and J.E. Raven put it,
Heraclitus, as Aristotle found, did not use the categories of formal logic, and tended to describe the same thing [the Logos] now as a god, now as a form of matter, now as a rule of behavior or principle which was nevertheless a physical constituent of things.  He was, indeed, more of a metaphysician than this Ionian predecessors, less concerned with the mechanics of development and change than with the unifying reality that underlay them.  (186).
To the extent that the Logos is “a physical constituent of things,” it is fire.  In fragment 30, Heraclitus declares, “This world-order [kosmos] did none of gods or men make, but it always was and is and shall be: an ever-living fire kindling in measures and going out in measures” (in Kirk, Raven, and Schofield 198).  Heraclitus’ fire seems to be a metaphor describing the universe as engaged in a process of perpetual becoming in which the only constant is the fact that everything changes from one form into another.  In the Cratylus dialogue, Plato has Socrates remark, “Heraclitus says, you know, that all things move and nothing remains still, and he likens the universe to the current of a river, saying that you cannot step twice into the same stream.” Heraclitus’ notion of the fire-logos and his famous saying about the impossibility of stepping in the same river twice metaphorically describe the same phenomenon: that is, the kosmos, which appears permanent and stable, is actually in a state of constant flux.  As a metaphor, the river aptly communicates how most people experience the flow of time and change around us.  Superficially, the river appears to be a permanent, stable entity.  But close, reflective observation reveals that it continually moves—that it is indeed not the same river from one moment to the next. 
Plato Plato or Platon (429-347 B.C.E.) is, by any reckoning, one of the most dazzling writers in the Western literary tradition and one of the most penetrating, wide-ranging, and influential authors in the history of philosophy. An Athenian citizen of high status, he displays in his works his absorption in the political events and intellectual movements of his time, but the questions he raises are so profound and the strategies he uses for tackling them so richly suggestive and provocative that educated readers of nearly every period have in some way been influenced by him, and in practically every age there have been philosophers who count themselves Platonists in some important respects. He was not the first thinker or writer to whom the word “philosopher” should be applied. But he was so self-conscious about how philosophy should be conceived, and what its scope and ambitions properly are, and he so transformed the intellectual currents with which he grappled, that the subject of philosophy, as it is often conceived — a rigorous and systematic examination of ethical, political, metaphysical, and epistemological issues, armed with a distinctive method — can be called his invention. Few other authors in the history of philosophy approximate him in depth and range: perhaps only Aristotle (who studied with him), Aquinas, and Kant would be generally agreed to be of the same rank.
Many people associate Plato with a few central doctrines that are advocated in his writings: The world that appears to our senses is in some way defective and filled with error, but there is a more real and perfect realm, populated by entities (called “forms” or “ideas”) that are eternal, changeless, and in some sense paradigmatic for the structure and character of our world. Among the most important of these abstract objects (as they are now called, because they are not located in space or time) are goodness, beauty, equality, bigness, likeness, unity, being, sameness, difference, change, and changelessness. (These terms — “goodness”, “beauty”, and so on — are often capitalized by those who write about Plato, in order to call attention to their exalted status; similarly for “Forms” and “Ideas.”)
The most fundamental distinction in Plato’s philosophy is between the many observable objects that appear beautiful (good, just, unified, equal, big) and the one object that is what beauty (goodness, justice, unity) really is, from which those many beautiful (good, just, unified, equal, big) things receive their names and their corresponding characteristics. Nearly every major work of Plato is, in some way, devoted to or dependent on this distinction. Many of them explore the ethical and practical consequences of conceiving of reality in this bifurcated way. We are urged to transform our values by taking to heart the greater reality of the forms and the defectiveness of the corporeal world. We must recognize that the soul is a different sort of object from the body — so much so that it does not depend on the existence of the body for its functioning, and can in fact grasp the nature of the forms far more easily when it is not encumbered by its attachment to anything corporeal. In a few of Plato’s works, we are told that the soul always retains the ability to recollect what it once grasped of the Forms, when it was disembodied (see especially Meno), and that the lives we lead are to some extent a punishment or reward for choices we made in a previous existence (see especially the final pages of Republic).
But in many of Plato’s writings, it is asserted or assumed that true philosophers — those who recognize how important it is to distinguish the One (the one thing that goodness is, or virtue is, or courage is) from the many (the many things that are called good or virtuous or courageous ) — are in a position to become ethically superior to unenlightened human beings, because of the greater degree of insight they can acquire. To understand which things are good and why they are good (and if we are not interested in such questions, how can we become good?), we must investigate the form of good.
Plato’s Dialogues     There is another feature of Plato’s writings that makes him distinctive among the great philosophers and colors our experience of him as an author. Nearly everything he wrote takes the form of a dialogue. (There is one striking exception: his Apology, which purports to be the speech that Socrates gave in his defense — the Greek word apologia means “defense” — when, in 399, he was legally charged and convicted of the crime of impiety. However, even there, Socrates is presented at one point addressing questions of a philosophical character to his accuser, Meletus, and responding to them. . . .
We are of course familiar with the dialogue form through our acquaintance with the literary genre of drama. But Plato’s dialogues do not try to create a fictional world for the purposes of telling a story, as many literary dramas do; nor do they invoke an earlier mythical realm, like the creations of the great Greek tragedians Aeschylus, Sophocles, and Euripides. Nor are they all presented in the form of a drama: in many of them, a single speaker narrates events in which he participated. They are philosophical discussions — “debates” would, in some cases, also be an appropriate word — among a small number of interlocutors, many of whom can be identified as real historical figures; and often they begin with a depiction of the setting of the discussion — a visit to a prison, a wealthy man’s house, a celebration over drinks, a religious festival, a visit to the gymnasium, a stroll outside the city’s wall, a long walk on a hot day. As a group, they form vivid portraits of a social world, and are not purely intellectual exchanges between characterless and socially unmarked speakers. . . . In many of his dialogues (though not all), Plato is not only attempting to draw his readers into a discussion, but is also commenting on the social milieu that he is depicting, and criticizing the character and ways of life of his interlocutors. Some of the dialogues that most evidently fall into this category are Protagoras, Gorgias, Hippias Major, Euthydemus, and Symposium. (from the Stanford Encyclopedia of Philosophy, online)
Homer (c. 750 BCE) was a legendary early Greek poet and aoidos (“singer”) traditionally credited with the composition of the Iliad and the Odyssey. The poems are often dated to the 8th or 7th century BC. However, whether Troy was an actual place, whether the Trojan War was an actual event, and whether Homer was an actual person is a matter of considerable controversy among experts in Classical languages and archeologists.  Without taking sides in this debate, this text refers to Homer as though he were an actual person for the sake of convenience.
Hesiod (Hess-ee-odd, c. 750 BCE) was reputed to be an early Greek poet and rhapsode who presumably lived around 700 BCE. As with Homer, little is known about Hesiod’s life and some have questioned whether he was a historical person; others have debated whether or not he lived before or after Homer, though the consensus among scholars seems to be that their lives, if in fact they ever lived, very probably overlapped. Hesiod serves as a major source of knowledge about Greek myth, ancient farming techniques, archaic Greek astronomy, and ancient time-keeping.
kosmos (KOZ-moss) Literally translated, “order,” but is typically used by philosophers to refer to the “world order.” English synonyms include “universe” or “cosmos.”
Zeus (Zoos or Zyoos) The youngest son of Cronus and Rhea, he was the supreme ruler of Mount Olympus and of the Pantheon of gods who resided there. Being the supreme ruler he upheld law, justice and morals, and this made him the spiritual leader of both gods and men. Zeus was a celestial god, and originally worshiped as a weather god by the Greek tribes. These people came southward from the Balkans circa 2100 BCE. He has always been associated as being a weather god, as his main attribute is the thunderbolt, he controlled thunder, lightning and rain. Theocritus wrote circa 265 BCE: “sometimes Zeus is clear, sometimes he rains”. He is also known to have caused thunderstorms. In Homer’s epic poem the Iliad he sent thunderstorms against his enemies. The name Zeus is related to the Greek word dios, meaning “bright.” His other attributes as well as lightning were the scepter, the eagle and his aegis (this was the goat-skin of Amaltheia).

Before the abolition of monarchies, Zeus was protector of the king and his family. Once the age of Greek kings faded into democracy he became chief judge and peacemaker, but most importantly civic god. He brought peace in place of violence and Hesiod (circa 700 BCE) describes Zeus as “the lord of justice.” Zeus was also known as “Kosmetas” (orderer), “Soter” (savior), “Polieos” (overseer of the polis, city) and “Eleutherios” (guarantor of political freedoms). His duties in this role were to maintain the laws, protect suppliants, to summon festivals and to give prophecies (his oldest and most famous oracle was at Dodona, in Epirus, northwestern Greece). As the supreme deity Zeus oversaw the conduct of civilized life. But the "father of gods and men" as Homer calls him, has many mythological tales.

His most famous was told by Hesiod in his Theogony, of how Zeus usurped the kingdom of the immortals from his father. This mythological tale of Zeus’ struggle against the Titans (Titanomachy) had been caused by Cronus, after he had been warned that one of his children would depose him. Cronus knowing the consequences, as he had overthrown his father Uranus. To prevent this from happening Cronus swallowed his newborn children Hestia, Demeter, Hera, Hades and Poseidon, but his wife Rhea (who was also his sister) and Gaia her mother, wrapped a stone in swaddling clothes in place of the infant Zeus. Cronus thinking it was the newborn baby swallowed the stone. Meanwhile Rhea had her baby taken to Crete, and there, in a cave on Mount Dicte, the divine goat Amaltheia suckled and raised the infant Zeus.

When Zeus had grown into a young man he returned to his fathers domain, and with the help of Gaia, compelled Cronus to regurgitate the five children he had previously swallowed (in some versions Zeus received help from Metis who gave Cronus an emetic potion, which made him vomit up Zeus” brothers and sisters). However, Zeus led the revolt against his father and the dynasty of the Titans, defeated and then banished them. Once Zeus had control, he and his brothers divided the universe between them: Zeus gaining the heavens, Poseidon the sea and Hades the underworld. Zeus had to defend his heavenly kingdom. The three separate assaults were from the offspring of Gaia: they were the Gigantes, Typhon (Zeus fought them with his thunder-bolt and aegis) and the twin brothers who were called the Aloadae. The latter tried to gain access to the heavens by stacking Mount Ossa on top of Mount Olympus, and Mount Pelion on top of Mount Ossa, but the twins still failed in their attempt to overthrow Zeus. As he did with the Titans, Zeus banished them all to Tartarus, which is the lowest region on earth, lower than the underworld.

According to legend, Metis, the goddess of prudence, was the first love of Zeus. At first she tried in vain to escape his advances, but in the end succumbed to his endeavor, and from their union Athena was conceived. Gaia warned Zeus that Metis would bear a daughter, whose son would overthrow him. On hearing this Zeus swallowed Metis, the reason for this was to continue to carry the child through to the birth himself. Hera (his wife and sister) was outraged and very jealous of her husband’s affair, also of his ability to give birth without female participation. To spite Zeus she gave birth to Hephaestus parthenogenetically (without being fertilized) and it was Hephaestus who, when the time came, split open the head of Zeus, from which Athena emerged fully armed.

Zeus had many offspring; his wife Hera bore him Ares, Hephaestus, Hebe and Eileithyia, but Zeus had numerous liaisons with both goddesses and mortals. He either raped them, or used devious means to seduce the unsuspecting maidens. His union with Leto (meaning the hidden one) brought forth the twins Apollo and Artemis. Once again Hera showed her jealousy by forcing Leto to roam the earth in search of a place to give birth, as Hera had stopped her from gaining shelter on terra-firma or at sea. The only place she could go was to the isle of Delos in the middle of the Aegean, the reason being that Delos was, as legend states, a floating island.

Besides deities, he also fathered many mortals. In some of his human liaisons Zeus used devious disguises. When he seduced the Spartan queen Leda, he transformed himself into a beautiful swan, and from the egg which Leda produced, two sets of twins were born: Castor and Polydeuces and Clytemnestra and Helen of Troy. He visited princess Danae as a shower of gold, and from this union the hero Perseus was born. He abducted the Phoenician princess Europa, disguised as a bull, then carried her on his back to the island of Crete where she bore three sons: Minos, Rhadamanthys and Sarpedon. Zeus also took as a lover the Trojan prince Ganymede. He was abducted by an eagle sent by Zeus (some legends believe it was Zeus disguised as an eagle). The prince was taken to Mount Olympus, where he became Zeus' cup-bearer. Zeus also used his charm and unprecedented power to seduce those he wanted, so when Zeus promised Semele that he would reveal himself in all his splendor, in order to seduce her, the union produced Dionysus, but she was destroyed when Zeus appeared as thunder and lightening. Themis, the goddess of justice bore the three Horae, goddesses of the seasons to Zeus, and also the three Moirae, known as these Fates. When Zeus had an affair with Mnemosyne, he coupled with her for nine consecutive nights, which produced nine daughters, who became known as the Muses. They entertained their father and the other gods as a celestial choir on Mount Olympus. They became deities of intellectual pursuits. Also the three Charites or Graces were born from Zeus and Eurynome. From all his children Zeus gave man all he needed to live life in an ordered and moral way.

Zeus had many Temples and festivals in his honor, the most famous of his sanctuaries being Olympia, the magnificent “Temple of Zeus,” which held the gold and ivory statue of the enthroned Zeus, sculpted by Phidias and hailed as one of the “Seven Wonders of the Ancient World.” Also the Olympic Games were held in his honor. The Nemean Games, which were held every two years, were to honor Zeus. There were numerous festivals throughout Greece: in Athens they celebrated the marriage of Zeus and Hera with the Theogamia (or Gamelia). The celebrations were many: in all, Zeus had more than 150 epithets, each one being celebrated in his honor.

In art, Zeus was usually portrayed as bearded, middle aged but with a youthful figure. He would look very regal and imposing. Artists always tried to reproduce the power of Zeus in their work, usually by giving him a pose as he is about to throw his bolt of lightening. There are many statues of Zeus, but without doubt the Artemisium Zeus is the most magnificent. It was previously thought to be Poseidon, and can be seen in the Athens National Archaeological Museum. (from the Encyclopedia Mythica)
Muses, The (MYOO-zuz) are the Greek goddesses who presided over the arts and sciences. They were believed to inspire all artists, especially poets, philosophers, and musicians. The Muses were the daughters of Zeus and Mnemosyne, the goddess of memory. The number of Muses varies over time; initially there was but one, and later there is mention of three: Melete, Mneme, and Aoede (the Elder Muses). They were nymphs in Pieria, western Thrace, and their cult was brought to Helicon in Boeotia by the Aloadae. Usually there is mention of nine muses: Calliope, Clio, Erato, Euterpe, Melpomene, Polyhymnia, Terpsichore, Thalia, and Urania, the Younger Muses.

The Muses were venerated throughout Greece, but more so in those areas with many wells and springs. The area of Boeotia, near Helicon, remained the favorite place of the Muses, and there they were more venerated than elsewhere. It is also the place of two well that were sacred to them, Aganippe and Hippocrene. Also Delphi and the Parnassus were their favorite places, and it was here that Apollo became their leader (musagetes).

The Muses sat near the throne of Zeus, king of the gods, and sang of his greatness and of the origin of the world and its inhabitants and the glorious deeds of the great heroes. From their name words such as music, museum, mosaic are derived. (from Encyclopedia Mythica)