Why did many greek philosiphers and writers reject the belief that events were caused by the whims of the gods?

Answer 1

The same reason scientists today reject the tenants of Creationism: their observations were telling them a different story.

By the time of Classical Greece, the one we think of with Philosphers and such, the Greeks, by and large, didn't necessarily think that the gods even existed, at least beyond a very basic acceptance of them. Most Philosophers and educated people, though. understood something that we don't necessarily know today. The Greek myths were based on Language and circumstance as much as the need to explain the unexplainable. They began to use the scientific process to observe natural phenomena and to understand why things happen.

Look at it like this: if you knew that the story of Apollo and Daphne wasn't about Apollo, Daphne, or the creation of the Laurel tree, but instead about why the morning dew disappears when the sun rises (which is what it is really about), then a simple scientific observation of the condition under which dew forms would easily show you why it disappears. Then you wouldn't need the divine explaination - you would know why it actually happens. Every religion goes through this process. Christianity is going through it now.