Here’s what Brian Armstrong says about Amyraut and lapsarian speculations:
"One of Amyraut’s favorite criticisms of orthodox theologians was of their metaphysical speculations, which he apparently felt resulted from their methodology. He was fond of emphasizing Calvin’s principle that God’s essence is incomprehensible for rational man, that “Men who . . . resolve to seek out what God is are but merely amusing themselves with insipid speculation.” In particular, Calvin cautioned that this principle must be applied in any consideration of the decree of election; it can be a source of consolation only if man begins with faith rather than the counsel of God. He says:
The election of God will be a fatal labyrinth for anyone who does not follow the clear road of faith. Thus, so that we may be confident of remission of sins, so that our consciences may rest in full confidence of eternal life, so that we may boldly call God our Father, under no circumstances must we begin by asking what God decreed concerning us before the world began. Rather we must begin by seeking what through His paternal love He has revealed to us through the Gospel. We must seek nothing more profound than that we become the sons of God.
Amyraut considered the orthodox doctrine of predestination, with all its speculation about the order of God’s decrees, an outright denial of this principle, and constantly called on Calvin in his desire to correct this orthodox tendency. Concerning the ordering of the decrees he makes the following incisive judgment:
... I am well aware that Calvin has said many things relating to the "impulsive" causes of the decrees of God, but as to their order I do not see that he has ever said a word. Why God has created man for hope of perpetual blessedness, he states that the only reason for this is His goodness. Why, man having fallen into sin and condemnation, God willed to send His son into the world to redeem men by His death, Calvin states that the only reason for this is an admirable love of God for mankind. Why He has elected some and passed by others in imparting the grace of faith, Calvin states that the only reason for this is the mercy and severity of God. Why God has preferred one individual to another in the distribution of this grace, Calvin does not recognize any other reason than solely the perfectly free will of God. Why He has willed to save believers and to condemn unbelievers unto eternal punishment, Calvin has thought that the reason for the latter must be taken from the justice of God whereas the reason for the former must be taken from His mercy...But what has been the order according to which God has arranged all these things in His eternal wisdom, when it is a question of His having proposed of thinking or willing what comes first or last, Calvin has never explained this nor has he the least interest in doing so.
Amyraut goes on to say that this order in the decrees is a matter in which the "secrets are so profound, and the abyss so impossible to explore, that whoever will undertake to know them would necessarily be swallowed up by them or will necessarily remain eternally deluded as being in a completely inexplicable labyrinth." Nor, he continues, has the Spirit of God furnished and light on this matter in the Word."
Brian Armstrong, Calvinism and the Amyraut Heresy (Wipf and Stock Publishers, 2004), p. 162-164.
John Quick reports what the Amyraldian party said before a French Synod (probably Alencon) this way:
"2) As to making distinct decrees in the council of God, the first of which is to save all men, through Jesus Christ, if they shall believe in him, the second to give faith unto some particular persons, Amyraut, along with Testard, declared, that they did this upon no other account than of accommodating it unto that manner and order which the spirit of man observeth in his reasonings for the succour of his own infirmity; they otherwise believing, that though they considered this decree as diverse, yet it was formed in God in one and the self-same moment, without any succession of thought or order of priority and posteriority." Quick's Synodicon, Vol. ii. p. 355.
If one wants to understand what Amyraut said about the decrees and their ordering, don't consult unreliable secondary sources that perpetuate a mythological Amyraut instead of the authentic Amyraut. Since there is only one of his works translated into english (his Brief Treatise on Predestination translated by Richard Lum in 1985 in partial fulfillment of his doctoral degree at Dallas Theological Seminary), he is severely misunderstood and misrepresented. If one wishes to research the man and his thought, consult those that have dealt with the primary sources and cite them carefully.
Incidently, R. L. Dabney and Herman Bavinck are other examples of Reformed men who have been critical of the tendency to speculate about the order of the decrees. Both of them rejected lapsarianism.
See the following posts for more about Amyraut's views:
These two posts should help to dispel the myth that Amyraut argued that Christ died for all equally without any qualifications. Too many are eager to erect this straw man in their arguments. On the contrary, Amyaut taught that the death of Christ was equally for all, but that Christ died unequally for all. In other words, there is no limitation in the death itself or the imputation of sin to Christ (it's equally sufficient to save all sinners), but there is a limit in Christ's intentions in suffering such an all sufficient death. He wholeheartedly affirmed the classic understanding of Christ suffering sufficiently for all (the general intent), but especially for the elect (which is the special intent).
If someone wants to call you an "Amyraldian" for holding a dualistic view, ask them why they are not calling you a "Calvinist." After all, Amyraut was echoing Calvin's views regarding Christ's satisfaction. Here's the dirty little secret: They are calling you an "Amyraldian" because they aren't even interpreting Calvin correctly and they want to alienate you from Reformed/Calvinistic circles. Instead of engaging Calvin's own categories as presented in the primary sources, they just tell you to consult their "experts." When someone calls me an Amyraldian, I just say "I am an Amyraldian in so far as he agrees with Calvin." :-) Or, I could say, "I am an Amyraldian in so far as he agrees with Calvin, Musculus, Bullinger, Zwingli, Ursinus, Ussher, Cameron, Davenant, Polhill, Baxter, Martinius, Calamy, Vines, Seaman, Arrowsmith, Preston, Watts, Marshall, Howe, Bunyan, Ryle, Dabney, Shedd, C. Hodge, Kuiper..." and on and on it goes. I might also add EVERY OTHER CHRISTIAN THAT LIVED PRIOR TO BUCER AND BEZA, with the possible exception of Gottschalk.