One of the more interesting theological debates of the twentieth century came from the question of whether or not humanity can be said to have a pure nature closed off to itself, and so possess in itself a natural end apart from God. The question, then, is whether or not humanity can retain a natural purity and glory unto itself, a natural perfection and good that has for itself an end other than in and with God.
To explore the concept of pure nature, and where the concept goes wrong, requires an understanding of what human nature is and what accounts for its natural goodness. Certainly, not all aspects of the theological speculation are erroneous, and indeed, much of what was attempted by those who taught it was based upon truths which all Christians should accept. The problem is, like so many errors, the elements of the truth lacked complementary elements of truth, so theological exploration of humanity became lopsided and the notion of a humanity which existed in and of itself apart from God was able to be established.
By nature, humanity is good, for all that God had made is good. Sin has weakened human persons, so that they live and act less than what they are to be by nature. If humans did not sin, they would live and act according to their nature, and because that nature is good, humanity would certainly find itself in and with a natural end which is good, and in that goodness, full of what makes them happy. For their happiness is found in the fulfillment of the natural goodness which lies in human nature. To achieve such purity of nature, humans need to be purified from sin, that is, anything which detracts them from fulfilling their proper good and therefore attaining their proper end.
Does this not suggest, then, that those who posited a pure nature are correct, that humanity has a natural goodness which they are to attain, and that alone would suffice for them? That once they are purified from sin, humans can find a natural happiness, residing in and amongst themselves, away from God?
The problem is that sin is what leads us away from God, so that there can be no sinless existence which also leads us away from God. It is a contradiction to ask if we can have a natural end, which is good and without sin, that turns us away from God. Goodness is found in our attaining the natural end God accorded for us, which is in and with him, for all good is itself derived from him, God, and for something to be good, therefore, is itself to participate in the goodness which is God. This is why all goodness is said to be given to us by God. “Every good endowment and every perfect gift is from above, coming down from the Father of lights with whom there is no variation or shadow due to change” (James 1:17 RSV). Only by attaining God, do we attain the goodness which God has established for us.This means, the question of whether or not we can have a good apart from God shows itself to be problematic in two ways. First, because sin is missing the mark which is found in and with God, so that to try to have a natural good apart from God is to be attached to a lesser good, an idol, and therefore to sin. It is impossible to talk about natural goodness in humanity which is also said to be found in and with sin. The two do not go together. The second contradiction, which affirms the first, is to assert a form of goodness which exists on its own apart from the foundation of all that is good, God. It would end up creating a rival good, a rival source of goodness, a rival God, which is why it would end up promoting sin, the sin of idolatry, to aim for such an end.
A natural existence which is an end in and of itself apart from God is an ontological contradiction. Now, this is not to say how and what kind of participation with the goodness of God is needed for humanity to be able to be said to be good, and pure in nature. There are many possible levels of participation and union with God. The notion of pure nature was established, in part, a way to allow God’s freedom in how he gives out his grace to humanity. The high level of deification which God accords to us is a gift, and as such, was beyond any possible expectation on our part. He could have created an end for humanity which gives a much lower-level participation in his goodness; it would have to be said to be with God and not apart from him, but it could have been that the end he established for humanity was the created good which he gave it as his creation, that is, the integral goodness found in humanity before its division from God due to sin. Scripture, in giving us a glimpse of unfallen humanity by the myth of Adam and Eve, showing how they walked with God, talked with God, interacted with God, outside of the dominion of sin, shows what the lowest-level end humanity could have had for its good. It is with God, not apart from God, a natural goodness which is given to it by God, by the way God in his grace created humanity, and established for itself a nature which is closed in on a derivative of God’s image and likeness as its proper function and end. It is with God, but it was also a closed system, and this could have been the proper end for humanity, what was to occur when we are saved from sin.