To introduce students to systematic philosophical and theological thinking in Hindu theistic traditions, this term’s lectures examine the Srimad Rahasyatrayasara (The Essence of the Three Holy Mysteries) of the 14th century south Indian Vaisnava theologian Vedanta Desika, in the context of earlier south Indian Vaisnavism. Some comparison and contrast will be made with another great classic, the Saiva Civananacittiyar (The Perfection of the Knowledge of Siva) of the 14th century Saiva theologian Arulnanti. (In a later series of lectures, Arulnanti’s work will be the prime focus.) Special attention will be paid to problems in interpretation and comparative methodology. These lectures are intended primarily for students in theology and religious studies; no background in Indian studies or theology required, although such background would be useful.