This work is based firmly on the work of three classical masters - St Thomas Aquinas, St John of the Cross, and St Teresa of Avila. The first part of Prof Jordan Aumann's magisterial Spiritual Theology is concerned with the theological principles of Christian holiness, while the second and major part derives from those principles' practical directives for the individual Christian's 'growth in holiness'. This text has already proved of great benefit to contemporary students and general readers seeking to inform and develop their own spiritual lives.