The Christian Apologists is the name given to those early Church
Fathers, whose principal task was to defend Christianity against
paganism (worship of false gods), against the Roman state, and
against Greek philosophy. Among these Christian Apologists are
the unknown author of The Preaching of Peter,
Aristides,
Quadratus,
Diognetus,
Justin Martyr,
Athenagoras,
Tatian,
Theophilus,
Irenaeus,
Hippolytus,
Felix,
Tertullian,
Arnobius, and
Lactanius.
His principal Latin writings are:
To the Martyrs (197 A.D.),
which is a brief exhortation to Christians facing martyrdom;
Apology (c.197 A.D.), which is magnificent
defense of Christianity in which he is principally concerned with
removing the political and social charges commonly brought against
Christianity;
Prescription of Heretics (De
Praescriptionibus Haereticorum, 203 A.D.), in which he disposes
of all heresy in principle, removing the necessity of arguing
against each in particular, denying them the appeal to the Scriptures,
which rightfully belong only to the churches founded by the apostles;
Against the Gnostics,
Against Valentinus,
Against Marcion,
Against the Marcionites,
On the Flesh of Christ,
On the Resurrection of the Body,
the Scorpiace (Serpent's Bite)
are attacks on Gnosticism (c.204-207 A.D.);
On the Soul (De Anima, c.206 A.D.) is
a lengthy learned rebuttal of Gnostic psychology and a positive
presentation of Tertullian's doctrine of the soul;
Against Praxeas (c.210 A.D.),
which is against the modalist Praxeas and is the most advanced
exposition to this date of the doctrine of the Trinity;
and a number of Montaist works written between 210 A.D. and 222 A.D.,
among which are
On Flight in Persecution (213 A.D.),
On Monogamy,
On Fasting, and
On Chastity (De Pudicitia).
From the first, Tertullian's practical works advocated a withdrawal from pagan society. His move to Montanism intensified this rigorism. For example, after reluctantly condoning remarriage in To His Wife (c.200 A.D.), he condemned it outright in On Monogamy (c.210 A.D.). And again, once he tolerated flight from persecution, but later in his On Flight in Persecution (213 A.D.) he outlawed any "unspiritual" avoidance of martyrdom.
Most of the writings of Tertullian are moral and disciplinary. From his early period, that is, up to about 206 A.D., and before there are any traces of Montanism, come On the (Lord's) Prayer, On Baptism, On Patience, On Penance, On Women's Dress, To his Wife, On the Virgin's Veil. They are homiletic-catechetical in form.
In his apologetic writings Tertullian opposed the blending of Greek philosophy and Christianity ("What has Jerusalem to do with Athens, the Church with the Academy, the Christian with the heretic?"). He held that reason and revelation are contradictory ("I believe because it is absurd."), and vigorously attacked the Greek philosophy, as well as Gnosticism in particular, and paganism generally. In this Tertullian differs from the strategy of most Christian Apologists who emphasized, in greater or lesser degree, a harmony between philosophy and the Christian faith. On Tertullian's view, that the Son of God died is to be believed because it is a contradictory, and that he rose from the dead has certitude because it is impossible. Yet, curiously, his doctrine of the relation of the body and soul, and of God and the world, he adopts a Stoic materialism where both God and the soul are view as spiritual matter. "Everything which exists is a bodily existence sui generic. Nothing lacks bodily existence but that which is non-existence"; "for who will deny that God is a body, although 'God is a Spirit'? For Spirit has a bodily substance of its own kind, in its own form". Tertullian seems here to be maintaining a materialistic doctrine and holding that God is really a material being, just as the Stoics considered God to be material. Some, however, have suggested that by "body" Tertullian often meant simply substance and that when he attributes materiality to God, he is really simply attributing substantiality to God. On this explanation, when Tertullian says that God is a corpus sui generis, that God is coprus and yet spiritus, he actually means that God is a spiritual substance; his language would be at fault, while his thought would be acceptable. One is certainly not entitled to exclude this explanation as impossible, but it is true that Tertullian, speaking of the human soul, says that it must be a bodily substance since it can suffer. In his Apology he gives as a reason for the resurrection of the body of the wicked that "the soul is not capable of suffering without the solid substance, that is, the flesh". It is probably best to say that, while Tertullian's language often implies materialism of a rather crass sort, his meaning may not have been that which his language would often imply. When he teaches that the soul of the infant is derived from the father's seed like a kind of sprout, he would seem to be teaching a clearly materialistic doctrine but this "traducianism" was adopted partly for a theological reason, to explain the transmission of original sin, and some later writers who are inclined to this same view, did so for the same theological reason, without apparently realizing the materialistic implications of the doctrine. Tertuallian's materialism provided a reasonable explanation for this "traducianism".