The Adversaries here are many, whether ancient, or more recent, against whom the truth just now confirmed must be maintained.
The ancient Origenists, dreaming that Souls, first created in heaven, obtained diverse bodies, various conditions, and life or death, according to their merits, whether good or evil, before the union both prepared now and foreseen further on: see EPIPHANIUS, Hæresi, LXIV, opera, tome I, pages 527, 528; JEROME, Epistola ad Avitum, opera, tome 2, page 152; DANÆUS on Augustine’s de Hæresibus, chapter XLIII, page 964b; and BUDDEUS, explaining the opinion of Origen in the matter of Predestination, Institutionibus Theologiæ dogmaticæ, tome 2, book V, chapter II, § 13, pages 1629-1631. ORIGEN, book V contra Celsum,page 271, denies Absolute Predestination: Καὶ τί τοῦτο πρὸς ἡμᾶς, τοὺς ἀπὸ τῆς ἐκκλησίας, κατηγορούτας τῶν εἰσαγόντων φύσεις ἐκ κατασκευῆς σωζομένας, ἢ κατασκευῆς ἀπολλυμένας, yet what is this against us, who are of the Church, and who make it an accusation against such as hold that certain natures are saved, and that others perish, in consequence of their natural constitution?; unless these things, as spoken against the error of Valentinus, of whom AUGUSTINE, de Hæresibus, chapter XI, and DANÆUS on him, page 931a, treat, be taken in a better way. According to the same, Philocalia, chapter XX, God makes vessels of honor, who shall purify themselves; and of dishonor, who shall leave themselves in uncleanness: more particularly, the common mass of souls before the creation of bodies was before God; and His will alone does not make vessels of ignominy or of honor, but the cause is in the inclination of the human Will to evil or good; and so Jacob and Esau had the causes of love and hatred πρὸ τῆς ἐνσωματώσεως, before embodiment, in themselves. Thus ORIGEN, who through this whole Chapter, after the passages of Sacred Scripture opposed to τῷ αὐτεξουσίῳ, free will, were reviewed, sets before his eyes: but these things appear thus to be said, as if salvation and damnation were not placed in our will; which he then attempts to refute.
The Pelagians, whose heresy sprouted almost with the birth of the fifth Century, and who held that the Cause of Predestination to Grace and Glory is the Foresight of Good works and perseverance in them, as a result of the right use of Free will, with the grace of the Apostolate excepted: see SPANHEIM’S Historiam Ecclesiasticam, Century V, chapter VII, § 1, columns 989-993.
The Semi-Pelagians, standing, as it were, between Pelagius and the Orthodox, the Massilienses by another name, who arose not long afterwards in Gaul, first at Massilia and neighboring places, about the year 430. These also urged a Predestination from this Foreseen, yet not merits, but efforts, a good will, the beginning of faith; in which manner these also attribute the distinguishing of men, not to divine εὐδοκίᾳ/ approval, but to man himself. To these Semi-Pelagians the specific dogma concerning the Predestination of Infants dying in that state is also said to belong; of course, this was also done from Foresight of the faith and life to be set up by them, if it had been allowed to them to arrive at a more advanced age: see SPANHEIM’S Historiam Ecclesiasticam, Century V, chapter VII, § 2, columns 993-995. Concerning the Pelagians and Semi-Pelagians, consult, in addition to the Writers of Ecclesiastical History, LEYDEKKER’SVeritatem Euangelicam triumphantem, tome I, book I, chapters VII, VIII.
 Celsus was a second century Greek philosopher and opponent of Christianity. Excerpts from his The True Word are found in Origen’s Contra Celsum.  Valentinus (c. 100-c. 160) was perhaps the most influential Gnostic of his day, with many followers. Although his work survives only in fragments, his system continued, albeit in modified forms, in his disciples. Valentinus divided humanity into the spiritual and the carnal, those able to receive spiritual things, and those not.  Massilia was a city at the mouth of the Rhone River.  Melchior Leydekker (1642-1721) studied under Voetius at Utrecht, and Hoornbeeck and Cocceius at Leiden. He was appointed Professor of Theology at Utrecht (1676).