Christian apologetics (, "verbal defense, speech in defense") is a branch of Christian theology that defends Christianity. Christian apologetics have taken many forms over the centuries, starting with Paul the Apostle in the early church and Patristic writers such as Origen, Augustine of Hippo, Justin Martyr and Tertullian, then continuing with writers such as Thomas Aquinas, Duns Scotus, William of Ockham and Anselm of Canterbury during Scholasticism. Blaise Pascal was an active Christian apologist during the 17th century. In the modern period, Christianity was defended through the efforts of many authors such as John Henry Newman, G. K. Chesterton and C. S. Lewis, as well as G. E. M. Anscombe. History Jewish precursors According to Edgar J. Goodspeed in the first century CE Jewish apologetic elements could be seen in works such as The Wisdom of Solomon, Philo's On the Contemplative Life and more explicitly in Josephus' Against Apion. Apostolic and post-apostolic period Christian apologetics first appear in the New Testament (e. g. Paul's preaching on Mars Hill in Acts 17:22-31). During the subapostolic age Christianity was already competing with Judaism as well as with various other religions and sects in the Greco-Roman world. Christian apologetics can be first seen in the ''Preaching of Peter'' (Gospel of Peter), but the first explicitly apologetic work comes from Quadratus of Athens (c. 125 CE) in which he writes a defense of the faith to emperor Hadrian. Only a fragment, quoted by Eusebius, has survived to our day:"But the works of our Saviour were always present, for they were genuine:—those that were healed, and those that were raised from the dead, who were seen not only when they were healed and when they were raised, but were also always present; and not merely while the Saviour was on earth, but also after his death, they were alive for quite a while, so that some of them lived even to our day." (Church History iv. 3. 2)One of the first comprehensive attacks on Christianity came from the Greek philosopher Celsus, who wrote The True Word (c.175 CE), a polemic criticizing Christians as being unprofitable members of society. In response, the church father Origen published his apologetic treatise Contra Celsum, or Against Celsus, which systematically addressed Celsus's criticisms and helped bring Christianity a level of academic respectability. In the treatise, Origen writes from the perspective of a Platonic philosopher, drawing extensively on the teachings of