What was Sir Isaac Newton's first name?

um... well.... Sir Isaac newton didn't have a middle name. im serious. belive me. i knew that for 3 years already becasue we learned about him 3 years ago. i studied alot about him.

[edit to improve]: During his time period, many people didn't have middle names, and some only had initials, such as Harry S. Truman. It was perfectly normal to have no middle name.