Heraclitus was a philosopher from Ancient Greece. From what I have heard and read, he sounds like he wasn’t the most sociable of people, and actually looked down on most people in terms of intelligence.
“Of this Word’s being forever do men prove to be uncomprehending, both before they hear and once they have heard it … Other men are unaware of what they do when they are awake just as they are forgetful of what they do when they are asleep.” (Diels-Kranz 22B1)
This view is probably best summed up by his death. The story goes that he started suffering from Edema (a condition where the body starts building up excess fluids). He set about asking the doctors around for their advice, but concluded he was smarter than them, and came up with his own treatment. This treatment (there’s a couple of versions of the story) involved him covering himself with cow manure and sitting in the hot sun. The thinking was probably that the manure would heat up and absorb his excess fluids, however he ended up dying in that pile of cow dung.
He is perhaps most famous for his idea of the “Logos”, which translates as ‘reason’ or ‘word’. Though open to interpretation, he described this Logos as the thing that governs the universe. He claimed it is the link between things that are opposites (i.e. hot and cold, good and evil, wet and dry, happy and sad). His idea was that opposites constantly change, like day to night and back to day, and create a balance.
Continuing on from this theme, he famously made a statement regarding the nature of a river…
“On those stepping into rivers staying the same other and other waters flow” (Diels-Kranz 22B12)
He is essentially pointing out that although the water particles in a river are constantly changing as it flows, the river is thought to be the same river.
That made me think about what actually goes into defining something, and reminds me of a conversation with a friend recently; ‘can a chocolate bar that’s melted into a different shape, be the same chocolate bar it originally was, if you were to rearrange it back into it’s original form?’
That’s my mini summary on Heraclitus. For further research, you may wish to read about his thoughts on fire!
Sources: Philosophize This! (http://www.philosophizethis.org) | Wikipedia (http://www.wikipedia.com) | Internet Encyclopedia of Philosophy (http://www.iep.utm.edu) | Britannica (http://www.britannica.com)