In Milton's Paradise Lost, it is Eve whom is first tempted by Satan. When he offers her the chance for God-like knowledge, the temptation is to great and she eats the forbidden fruit. If it were the other way around, and Adam first tempted, would he have also fallen for the trick? By looking at the ever-going argument of free will, and studying similar writings, it can be discovered that it was not Eve that caused the fall of humanity but the desire for knowledge.
Humanity was originally created with free will. It is evident because Eve had the ability to sin. It was her decision to sin or not sin, and she decided to eat the fruit. Adam also had the free will to decide to sin or not. If he had chosen not to eat the fruit, it would have only been Eve who would have been put to death for her sin, and not the both of them. Genesis 1:31 says, "God saw all that he had made and it was very good."" Adam being part of this creation would have also been considered very good, implying he had the ability to be good. If he had the ability to be good, he must have had the ability to be bad. How could he be good if he did not have the ability to be bad? Thus proving Adam and Eve had free will to sin. .
Before Eve and Adam eat the forbidden fruit, Genesis 1:27 says, "God created man in his own image; in the image of God He created him; male and female He created them."" Unfortunately, When Adam and Eve ate the forbidden fruit they no longer possessed free will. They no longer had the choice to sin or not. After the fall, all of humanity was born into sin. This can be seen in Genesis 5:3 which speaks of Adam's son, ".and begot a son in his own likeness, after his image."" But what would tempt Adam and Eve to give up this power? What would tempt them to give up this power to decide wrong from right? The desire for knowledge was behind their deceitful act. .
In Paradise Lost, Satan tempts Eve with happiness before he even shows her the tree.