The Synopsis Purioris Theologiae [Synopsis of a Purer Theology] Buy 1625 was a textbook in systematic theology that gave an exhaustive, yet concise, presentation of Reformed theology as it was conceived in the first decades of the seventeenth century. The Synopsis had originated as a series of 52 disputations held in Leiden University (in the Netherlands) between 1620–1624. In it the Leiden professors Johannes Polyander (1568-1646), Andreas Rivetus (1572-1651), Antonius Walaeus (1573-1639), and Antonius Thysius (1603-65) continued a tradition from before the Synod of Dort (1618-1619). All of them except Rivet were delegates at that same Synod.
The Leiden Synopsis, vol. 1, edited by Dolf te Velde, translated by Riemer Faber, published by Brill, 2015, originally printed in 1625.
6. About the Nature of God and his Divine Attributes, p. 179
Author: Antonius Thysius
Love is whereby He wills and approves the good in created beings and He abides in it; He wills, is able to present, and actually presents himself kind and gracious (though He does not have to do so). When applied to human being it is called philanthropy (Malachi 1:2,3; Titus 3:4). Compassion and mercy are whereby He wills, is able to provide, and actually does provide help to those who are wretched (Psalm 136:1, etc.; Exodus 34:5,6,7).
11. On the Providence of God, p. 277
Author: Andreas Rivetus
Here is a place for a distinction in the ways God handles providence when He implements it—it is either effective, or permitting. The first is the one whereby God works effectually, and in all things generally and individually perfects his work (namely all things both general and specific in nature), not only the essential good—the substances, motions, actions and completions of things—but also the moral good, such as all civic and spiritual virtues. Because, as the highest good, He is also the author and source of all good.
[Webmaster’s Note: The implications of this statement of the Synopsis is that God is the author of the good in all of his creatures, including the civic virtues of the reprobate. This is also known as the doctrine of Common Grace.]
22. On the Gospel
Author: Johannes Polyander
p. 559, this quote was compiled by Andrew Myers.
Secondly, the word [Gospel] is used for the joyful teaching and preaching of the reconciliation of sinful people with God through the free remission of sins obtained for them by the expiatory death of Christ. It is offered to one and all without restriction; it is revealed to the poor in spirit and to little children, and actually applied individually to those who believe, for their salvation and the revelation of God’s mercy and accompanying justice, and for his eternal praise (1 Corinthians 9:14,15, etc.).
The impelling cause whereby God within Himself moves to declare the Gospel is God’s unrestricted mercy and goodwill with which he purposed to embrace the wretched human race that had fallen into sin by the guilt of Adam.
The object to which God reveals his unrestricted mercy and goodwill in his Gospel is the wretched human race that had fallen headlong into deadly sin by the Devil’s deception, and to which God announced the grace of his redemption, sometimes directly and sometimes indirectly.
[Webmaster’s Note: Note that the Synopsis is not speaking of the elect (who are nowhere in the passage’s larger context), but of the indiscriminate declaration of the gospel to man generally.]
The destruction of unbelievers, however, is not a goal of the Gospel; that is an unconnected outcome from elsewhere, from their sins. For in his Gospel God declares that he takes no delight in the destruction of any sinner, but he delights in transferring everyone to salvation through repentance and faith from the power of darkness into the kingdom of his beloved Son, Jesus Christ.
23. On the Old and the New Testament
Author: Andreas Rivetus
And the Law is placed over against the promise in such a way that if the inheritance comes by the former, then it cannot come by the latter (Galatians 3:18). The same reason exists for the contrast between the Law of works and the Law of faith (Romans 3:27). The first of these is understood as teaching salvation that is promised on the condition “that you do all these things,” while the second teaches that the same salvation is offered on the condition “that you believe.” God freely grants that condition so that whoever is justified fulfills it.
A third difference is added in this, that when the old testament was handed down it was wrapped up in a shadowy keeping of ceremonies that possessed no efficacy of itself; and the various rites and figures in it were a means of foreshadowing Christ as yet to come. But in the new testament we are offered to behold Him with his face uncovered, and the truth of the things themselves and his body are displayed in the here and now.
Having rejected these false teachings, we take our repose in this dispensation of God, whereby God has arranged the law and the promise in such a way that we regard the former as one that condemns and we seek the latter for the comfort it brings. The former demands while the latter forgives, the former finds blame while the latter embraces in love. Nevertheless in both the old and the new testaments he has offered the same, the only way to salvation through his grace in the mediator Christ, having changed only their circumstantial qualities and the ways in which He dispensed them.
From the 1642 edition. Both of these quotes were compiled by David Ponter
p. 356, as translated by Lee Gatiss
Moreover, the end, object, and “for whom” (? or cui) of satisfaction is only the Elect and true believers of both the Old and the New Testament. For although with respect to the magnitude, dignity, and sufficiency of the price, considered in itself, it may be extended to all people, yet it is particularly a payment for those whom the Father has chosen and given to the Son, who by the gift of God will believe in God and his Son. Wherefore Scripture everywhere says that He spent Himself “for his own,” and “for us,” “for the sheep,” and “the Church.” Matthew 20:28, 26:28; 1 John 3:16; Acts 20:28 etc.
Section 24, 54-55, as quoted in Heinrich Heppe, Reformed Dogmatics, p. 185.
For this to be understood correctly, careful note must be taken that this praeterition [passing over in reprobation] does not remove or deny all grace in those passed over, but that only which is peculiar to the elect. But that which through the dispensation of common providence, whether under the law of nature or under gospel grace, is dispensed to men in varying amount, is not by this act of praeterition removed but is rather presupposed; the non-elect are left under the common government of divine providence and the exercise of their own arbitrium [will].
R. Scott Clark on the Leiden Synopsis
R. Scott Clark, “Janus, the Well-Meant Offer of the Gospel and Westminster Theology”, in The Pattern of Sound Doctrine: Systematic Theology at the Westminster Seminaries; Essays in Honor of Robert B. Strimple, edited by David VanDrunen Buy 2004, p. 171-2
First in Synopsis Purioris Theologiae (Leiden, 1625), a compilation of  school disputations by Johannes Polyander (1568-1646), Andreas Rivet (1572-1651), Antonius Walaeus (1573-1639), and Antonius Thysius (1603-65), of whom only Rivet was not delegated to the Synod [of Dort, which had taken place in 1618-9], we find the archetypal/ectypal distinction taught (in Disputatio I, De sacrosancta theologia [Disputation 1, Of Holy Theology]) and from it a corollary, the internal/external distinction in the ordo salutis [order of salvation].
(Footnote: Synopsis Purioris Theologiae, ed. H. Bavinck (Leiden: D. Donner, 1881), 2-3, 294-300.)
Under Disputatio XXX, De hominum vocatione ad salute [Disputation 30: Of Man’s Calling to Salvation], in Article 21, the Synopsis taught that through the “preaching of the Gospel” (an external operation performed according to ectypal theology) the “good” (bonum) of salvation (Art. 20) is “offered” (offertur), and the Holy Spirit “kindles” (accendit) “genuine knowledge” (serias cogitations) and “pious desire” (pium desiderium) in our hearts.
(Footnote: Ibid., 296.)
Not surprisingly, the language of the Leiden Synopsis was virtually identical to that of Dort.