What did the philosophers on Mars Hill do day in and day out?
According to the account of Paul on Mars Hill, the philosophers there spent their days continually dreaming up some new thing to philosophize about. They were consumed with novelty and intellectual speculation rather than the gospel. This reflects the Greek cultural obsession with philosophy that Paul encountered, in contrast to his simple proclamation of the cross.
Les explains that when Paul confronted the philosophers on Mars Hill, what he ran into was that all those philosophers did day in and day out was to dream up some new thing that they could philosophize about. Paul, by contrast, said he did not come with a philosophy or some new thing; he came with the gospel, which is the cross of Christ. Les notes that this was part of the Greek culture, and the Greeks were all hung up on philosophy. The preaching of the cross is foolishness to those who perish, but it is the gospel that transformed people, not intellectualism or the wisdom of words.