 After studying Latin with local ministers and schoolmasters in Guilford, Clinton and Middleton, including Jared Eliot, Johnson left Guilford at age 13 to attend the Collegiate School at Saybrook (now Yale University) in 1710.There he studied the Reformation logic of Petrus Ramus and the orthodox Puritan theology of Johannes Wolleb (Wollebius) and William Ames.He graduated in 1714 as class Valedictorian with a bachelor's degree, and in 1717 was awarded a master's degree.