Book excerpt: This version of Aquinas' Summa contra Gentiles contains the annotations of Joseph Rickaby, early 20th century Jesuit priest and philosopher, alongside the main text. Aquinas meant his treatise to serve as an apologetics handbook for missionaries and philosophers defending the Christian faith against those outside of or hostile to Christianity. The style and content of Aquinas' arguments were particularly relevant to his time. The major religious communities in close proximity to the Christian West- Jewish and Islamic-had developed their various theological views using borrowed terms and ideas from Aristotelian philosophy just as Aquinas himself had.