Thomas is one of the most important theologians in the two-thousand-year history of Christianity. He wrote at a time when theology and philosophy travelled essentially the same path, and his integration of theology and philosophy formed the consensus of medieval Christianity. Aquinas was a Dominican Catholic whose work integrated "reason" and "revelation" in ways that shaped Roman Catholic theology for nearly 700 years. His work deeply influenced the Council of Trent (1549-1566) and also impacted the magisterial Protestant reformers (though in different ways than in Roman Catholicism). Philosophically, Aquinas helped reintroduce the work of the Greek philosopher Aristotle to medieval philosophy and theology. This Libguide offers important sources for study and reflection on Thomas and his philosophical/theological synthesis. It is not exhaustive, given the massive literature about Thomas published over the past several hundred years. Instead, it focuses on accessible primary sources and introductory works, and contains an online resources section that links to important descriptive and bibliographical information about Thomas.