Justin Martyr.

One of the Christian apologists.

Attributed text(s).
Dialogue with Trypho.
Apology (in two parts).
On the Resurrection.
Discourse to the Greeks.
On the Sole Government of God.
Hortatory Address to the Greeks.
On the Soul (?).
Against Marcion.
Against All Heresies.
Psaltes.
Refutation.

Available text(s).
Skeptik (Greek only).
CCEL:

Related text(s).
Martyrdom of Justin (in Greek and Latin from Christian Hospitality, very large file in .pdf; in English from the CCEL).

Useful links.
Justin Martyr at EarlyChurch.
Justin Martyr in the Catholic Encyclopedia.
Justin Martyr at Early Christian Writings.

Justin Martyr was a Christian apologist who lived in Rome at the middle of century II. He certainly authored the Apology (in two parts) and the Dialogue with Trypho. English translations are available online at the Christian Classics Ethereal Library. The attribution to Justin of On the Resurrection, Discourse to the Greeks, On the Sole Government of God, and Hortatory Address to the Greeks is disputed. There are rather many other later works which have also been attributed to him. Also see the Justin Martyr page at Early Christian Writings, and refer also to my page on the gospel details in Justin Martyr.

From Irenaeus, Against Heresies 1.28.1:

Qui cum esset Iustini auditor, in quantum quidem apud eum erat, nihil enarravit tale.

[Tatian] was a hearer of Justin, and as long as he was with him he narrated nothing of the kind [that is, nothing like encratism].

From Irenaeus, Against Heresies 4.6.2:

Et bene Iustinus in eo libro qui est ad Marcionem ait: Quoniam ipsi quoque domino non credidissem, alterum deum annuntianti praeter fabricatorem et factorem et nutritorem nostrum. sed quoniam ab uno deo, qui et hunc mundum fecit, et nos plasmavit et omnia continent et administrat, unigenitus filius venit ad nos, suum plasma in semetipsum recapitulans, firma est mea ad eum fides, et immobilis erga patrem dilectio, utraque deo nobis praebente.

In his book against Marcion, Justin says well: I would not have believed the Lord himself if he had announced any other than him who is our framer, maker, and nourisher. But, because the only begotten son came to us from the one God, who both made this world and formed us, and contains and administers all things, summing up his own handiwork in himself, my faith towards him is steadfast, and my love toward the father immoveable, God bestowing both upon us.

From Irenaeus, Against Heresies 5.26.2 (Greek text from Eusebius, History of the Church 4.18.9; that portion of the quotation that exceeds Irenaeus and Eusebius comes from the catena assembled by Cramer in 1844):

Bene Iustinus dixit quoniam ante domini adventum nunquam ausus est Satanas blasphemare deum, quippe nondum sciens suam damnationem,* quoniam et in parabolis et allegoriis a prophetis de eo sic dictum est. post autem adventum domini, ex sermonibus Christi et apostolorum eius discens manifeste quoniam ignis aeternus ei praeparatus est ex sua voluntate abscendenti a deo, et omnibus qui sine poenitentia perseverant in apostasia, per huiusmodi homines blasphemat eum deum qui iudicium importat quasi iam condemnatus, et peccatum suae apostasiae conditori suo imputat, et non suae voluntati et sententiae; quamadmodum et qui supergrediuntur leges, et postea poenas dant, queruntur de legislatoribus, sed non de semetipsis.

* Eusebius proceeds only to this point.

Και καλως ο Ιουστινος εφη οτι προ μεν της του κυριου παρουσιας ουδεποτε ετολμησεν ο Σατανας βλασφημησαι τον θεον, ατε μηδεπω ειδως αυτου την κατακρισιν,¹ δια το εν παραβολαις και αλληγοριαις κεισθαι· μετα δε την παρουσιαν του κυριου εκ των λογων αυτου και των αποστολων μαθων αναφανδον οτι πυρ αιωνιον αυτω ητοιμασται κατ ιδιαν γνωμην αποσταντι του θεου, και πασι τοις αμετανοητως παραμεινασι εν τη αποστασια, δια των τοιουτων ανθρωπων βλασφημει τον την κρισιν επαγοντα κυριον, ως τω εκτικοτι αυτον αποκαλει, αλλ ου τη ιδια αυθαιρετω γνωμη· ως και οι παραβαινοντες τους νομους, επειτα δικας διδοντες, αιτιωνται τους νομοθετας, αλλ ουχ εαυτους.² δια τουτο ως λεων περιπατει ωρυομενος, παντας φιλονεικων ελκυσαι προς την ιδιαν απωλιαν.

¹ Eusebius gives the quotation only up to this point; the rest of the Greek quotation is from the catena assembled by Cramer.
² The Latin translation of Irenaeus goes only up to this point.

Well has Justin said that before the advent of the Lord Satan never dared to blaspheme God, inasmuch as he did not yet know his own damnation,¹ since it was spoken about him in parables and allegories by the prophets; but after the advent of the Lord, learning manifestly from the words of Christ and his apostles that eternal fire has been prepared for him for his voluntary absence from God, as well as for all who perservere in apostasy without repentance, he now blasphemes, by means of such men, the God who brings judgment as if already condemned, and imputes the sin of his apostasy to his maker, and not to his own voluntary disposition; just as it is with those who break the laws and afterward they punish them, they throw the blame upon the legislators, but not upon themselves.² On this account he walks about as a roaring lion, contentiously wanting to draw all men into the same destruction.³

¹ Eusebius goes only this far; the rest is from Irenaeus and Cramer.
² Irenaeus goes only this far; the rest is from Cramer alone.
³ Refer to 1 Peter 5.8.

Tertullian, Against the Valentinians 5.1 (English translation slightly modified from that of Mark T. Riley):

Mihi autem cum archetypis erat limes principalium magistrorum, non cum affectatis ducibus passivorum discipulorum. nec undique dicemur ipsi nobis finxisse materias quas tot iam viri sanctitate et praestantia insignes, nec solum nostra antecessores sed ipsorum haeresiarcharum contemporales, instructissimis voluminibus et prodiderunt et retuderuntut Iustinus, philosophus et martyr; ut Miltiades, ecclesiarum sophista; ut Irenaeus, omnium doctrinarum curiosissimus explorator; ut Proculus noster, virginis senectae et Christianae eloquentiae dignitas, quos in omasi opere fidei quemadmodum in isto optaverim adsequi.

My exposition will be limited to the original teachings of their chief teachers; it will not include the high-flying leaders of the mass of followers. I hope no one will say because of this limitation that I have invented this material for the occasion. No indeed, many men who were renowned for their holiness and their leadership, who were not only our predecessors but also contemporaries of those very heresiarchs, have exposed and refuted them in learned volumes. I refer to Justin, philosopher and martyr, Miltiades, that churchly sage, Irenaeus, an eager discoverer of all doctrines, and our own Proculus, the living exemplar of a chaste old age and of Christian eloquence. In their footsteps I might hope to follow in all works of faith, just as I do in this work.

Eusebius, History of the Church 4.18.9:

Ουτωσι δε σπουδης ειναι αξιοι και τοις παλαιοις εδοκουν οι τανδρος λογοι ως τον Ειρηναιον απομνημονευειν αυτου φωνας, τουτο μεν εν τω τεταρτω προς τας αιρεσεις αυτα δη ταυτα επιλεγοντα· Και καλως ο Ιουστινος εν τω προς Μαρκιωνα συνταγματι φησιν οτι αυτω τω κυριω ουκ αν επεισθην αλλον θεον καταγγελλοντι παρα τον δημιουργον. τουτο δε εν τω πεμπτω της αυτης υποθεσεως δια τουτων· Και καλως ο Ιουστινος εφη οτι προ μεν της του κυριου παρουσιας ουδεποτε ετολμησεν ο Σατανας βλασφημησαι τον θεον, ατε μηδεπω ειδως αυτου την κατακρισιν.

And the discourses of the man were thought so worthy of study even by the ancients that Irenaeus makes mention of his words: for example, in the fourth [volume] against the heresies, where he writes as follows: And Justin well says in his work against Marcion that he would not have believed the Lord himself if he had preached another God besides the demiurge [or creator]; and, for example, in the fifth book of the same work he says: And Justin well said that before the advent of the Lord Satan never dared to blaspheme God, because he did not yet know his own condemnation.

Jerome, On Famous Men 23:

Iustinus philosophus, habitu quoque philosophorum incedens, de Neapoli urbe Palaestinae, patre Prisco Bacchio, pro religione Christi plurimum laboravit, in tantum ut Antonino quoque Pio et filiis eius et senatui librum contra gentes scriptum daret, ignominiamque crucis non erubesceret. et alium librum successoribus eiusdem Antonini, M. Antonino Vero et L. Aurelio Commodo. exstat eius et aliud volumen contra gentes, ubi de daemonum quoque natura disputat, et quartum adversus gentes, cui titulum praenotavit ελεγχος, sed et alius de monarchia dei, et alius liber quem praenotavit psalten, et alius de anima, dialogus contra Iudaeos, quem habuit adversus Tryphonem principem Iudaeorum, sed et contra Marcionem insignia volumina, quorum Irenaeus quoque in quarto adversus haereses libro meminit, et alius liber contra omnes haereses, cuius facit mentionem in apologetico quem dedit Antonino Pio. hic cum in urbe Roma haberet διατριβας, et Crescentem cynicum, qui multa adversum Christianos blasphemabat, redarguere gulosum et mortis timidum, luxuriaeque et libidinum sectatorem, ad extremum studio eius et insidiis accusatus quod Christianus esset pro Christo sanguinem fudit.

Justin the philosopher, wearing the garb of the philosopher, from Neapolis, a city of Palestine, Priscus Bacchius being his father, laboured much on behalf of the religion of Christ, insomuch that he delivered to Antoninus Pius and his sons and the senate a book written against the nations, and did not shun the ignominy of the cross. He addressed another book also to the successors of this Antoninus, Marcus Antoninus Verus and Lucius Aurelius Commodus. Another volume of his against the gentiles [or nations] is also extant, where he discusses the nature of demons, and a fourth against the gentiles which he entitled the refutation, and yet another on the monarchy of God, and another book which he entitled Psaltes, and another on the soul, the dialogue against the Jews, which he held against Trypho, a leader of the Jews, and also notable volumes against Marcion, which Irenaeus also mentions in the fourth book against heresies, and also another book against all heresies, of which he makes mention in the apology which he gave to Antoninus Pius. He, when be had held diatribes in the city of Rome, and had convicted Crescens the cynic, who said many blasphemous things against the Christians, of gluttony and fear of death, and had proved him a follower of luxury and lusts, at last, accused of being a Christian through the efforts and wiles of Crescens he shed his blood for Christ.