Genesis two seems to clearly present Adam with a choice between obedience and blessing (Gen 2:16) and disobedience and judgment (Gen 2:17). Then, when Adam and Eve did eat (Gen 3:6), God rightly judged them, and they died. Consequently, they lost all the blessings God had granted them while living in the garden because he held them responsible for their actions (Gen 3:11-13, 16-19, 22-24).
According to compatibilism (Calvinism’s view of moral freedom), Adam and Eve freely chose to eat of the tree, which was a sin against God. Equally true of compatibilism is that, given their nature and past, they could not have refrained from sinning in the moral moment of decision because the desire from which they freely chose was a predetermined desire given their past and nature (Calvinists often omit this component of compatibilism).
Consequently, while God was not the immediate cause of their sin, he did desire they freely choose to sin. God’s choice is evident by Adam and Eve’s predetermined past and nature, from which inexorably emanated the predetermined desire to freely choose to eat of the tree. Consistent with compatibilism, had God desired them to refrain from sinning, he would have given them a nature and past emanating that desire from which to freely choose.
That being the case, God did clearly desire for them to sin as well as all the consequences of sin to befall his creation. This desire is more than just the desire to permit the fall, with which Extensivists (non-Calvinist) agree, but rather it is that he desired it in such a way that he determined it to happen. Therefore, Adam and Eve were the proximate cause (immediately before) of their choice to sin, but God, and only God, is the ultimate cause.
According to libertarian moral freedom (which Extensivism embraces), Adam and Eve freely chose to eat of the tree and sin against God. Equally true of libertarianism is that given their past, which includes their nature, they could have and should have refrained from sinning since they could have chosen to eat or refrain, and whatever they did choose, they could have chosen differently.
God’s desire for them to refrain is evident from their ability to live in holy fellowship with him, their placement in the garden, the warning not to eat, and the consequence if they did. Even though God knew they would misuse their freedom and sin, he never desired that for them since he is essentially holy and good (1 Pet 1:15; 3 John 11) and is pleased when his creation acts righteously (Heb 13:16). Therefore, he always desires holiness and righteousness.
Some Calvinists seek to extricate themselves from the dilemma of compatibilism wherein man may be the proximate cause, but God is undeniably the ultimate cause. They do this by contending that man had a libertarian choice, prior to the fall, in whether to eat of the tree or not and then once fallen, they strap him with compatibilism. The reason for invoking the use of libertarian freedom is because, as seen in its entailments, one so endowed is the efficient cause of his actions. This means that God is in no way implicated even as an ultimate cause in the sin of a libertarian free being, which is not true of a compatibly free being. But such a move does not work for three reasons.
One, Calvinists often claim God cannot know the acts of libertarian free beings (contingencies) or be sovereign over libertarian free beings. But if he could know and be sovereign over contingencies in the pre-fall era, he could do so in the post-fall era. This raises the question, why do Calvinists so adamantly oppose libertarian freedom now? Such a shift moots Calvinism’s argument for compatibilism and against libertarianism.
Two, moral freedom is not extrinsic (not essential) to the nature of a human, but rather it is as intrinsic (essential) to human nature as being created in the image of God. Peter Kreeft comments, “One gives a polish to a table, or a pony to a schoolboy, but one does not give three sides to a triangle or free will to a human being. Free will is a part of our essence. There can be no human being without it. The alternative to free will is not being a human but an animal or a machine.”
Three, since the moral freedom of human beings, is intrinsic and not extrinsic, and if their nature so drastically changed in the fall (from God’s original creation to what they are after the fall), so as to change their essential created nature (from libertarianly free morally to compatibly free morally), redemption would not be for mankind who fell in the garden. It would not be for the created humans who became the sinful created humans, but for an ersatz (imitation) human. Accordingly, God’s plan of salvation would not demonstrate an all-loving, powerful, and merciful God; it would fail to save the precise humans who sinned.
Therefore, according to Calvinism with its commitment to compatible moral freedom, God is the ultimate cause of every good and evil thought, intention, and act, which always leaves humans making determined free choices in which they could not do otherwise–given their same past. This micro-determinism does not end when someone becomes a Christian because it does not originate from their sinfulness, but rather from the determined creative will of God. This means that if a Christian prays or does not pray, witnesses or does not witness, gives or does not give, steals, rapes, or blasphemes, it is ultimately because God determined that he would; thus, entailed in Calvinism, it is impossible to absolve God from being the responsible ultimate cause for every sin and evil.
 COMPATIBILISM: Determinism and moral responsibility are compatible, hence the name. This compatibility is not achieved by compatibilism being less deterministic than hard determinism. Rather, it is achieved by defining free choice to mean as long as a person chooses according to his greatest desire, he has made a free choice for which he is morally responsible; even though given the same past, he cannot choose differently in the moral moment of decision.
Consequently, the difference between compatibilism (soft determinism) and hard determinism is not to be found in the levels of the deterministic nature of each since they are the same. Rather, the difference is compatibilism simply contends people are morally responsible for their choices if they are made according to their greatest desire, and hard determinism says they are not. Therefore, moral responsibility is the product of defining free choice as a person acting in accordance with his greatest desire even though the desire is determined.
 LIBERTARIAN: Man is not determined. He has the actual ability to choose between accessible options, at least in some scenarios. Libertarians contend determinism is not compatible with moral responsibility. Man possesses actual otherwise choice and can, therefore, act or refrain in the moral moment of decision, given the same past within a given range of options.
Extensivism argues God endowed man with this ability, which is an aspect of being created in the image of God. God determines the range of options. Adam’s range of options, the result of creative grace, was greater than mankind’s options after the fall. Fallen man can still choose between options, but the range of options is less than man had prior to the fall. This lessening includes losing the ability to make choices that are inherently righteous or spiritually restorative (making one right with God) based solely on creative grace. In order to make an inherently righteous choice or one that is spiritually restorative, God had to provision redemptive grace, grace enablements which he did.
 Peter Kreeft and Ronald K. Tacelli, Handbook of Christian Apologetics: Hundreds of Answers to Crucial Questions (Downers Grove, IL: InterVarsity , 1994), 3.