William Ames (known to Latin readers as Guilielmus Amesius) was an English theologian and casuist whose writings greatly influenced Puritan thinking in the seventeenth century and beyond. He was also one of the foremost Ramists, or followers of the sixteenth-century Huguenot and educational reformer Pierre de La Ramée (known in Latin as Petrus Ramus). A lifelong and uncompromising Puritan, Ames spent the second half of his life in the Netherlands, where his nonconformism was better tolerated than in England. He wrote several important works on theology, logic, casuistry, and homiletics, all of which are marked by his concern for "practical divinity," or correct doctrine joined with correct living.

Ames was born in Ipswich, Suffolk, in Puritan East Anglia, in 1576 to William Ames, a merchant, and Joane Snelling Ames, also from a merchant background. He was orphaned at a young age but raised by a generous uncle...