Hi Bob!
Fortunately, this is not a dodgy forum. :) I hope you're not desperate because this homework is due tomorrow ;) . Sometimes there's no one here to answer questions right away.
One strong influence on Lewis was his teacher W.T. Kirkpatrick. Mr. Kirkpatrick tutored him from the ages of 16-18 (roughly). Lewis said that Kirkpatrick, who was not a Christian, taught him how to think and argue. You can read more about what Lewis had to say about him in Surprised by Joy.