One argument that I have heard against the position of "literal days of creation" is that the Literal-day view utilizes "Enlightenment hermeneutics." According to what I have read, evidently the Ancient and Medieval Church were not interested in reading Genesis as "literal narrative." Rather, they were interested in using Genesis as a polemic against the non-narrative pagan myths especially those in Platonism and Gnosticism. While certainly they will concede that the Ancient and Medieval Church believed in the historicity of Genesis, they will contend that the view that Genesis was to be interpreted as literal narrative comes from the Enlightenment.
In this post, I would just look at the issue from a hermeneutical perspective. The other allegations are so vacuous as to be laughable. It is from the Enlightenment that we get theories such as the Local Flood and the view that the Genesis stories especially in chapters 1 to 11 are myths. Since these rather conservative folks embrace a non-literal view of the Creation days and some of them embrace a local flood model (both theories promoted by the Enlightenment), it is more likely that their views come from the Enlightenment than those of their opponents.
Nevertheless, from the hermeneutical standpoint, what can we say of the allegations? Did the "literal narrative" hermeneutics really originate during the Enlightenment? To this, let us look at the example of Origen, probably the most reviled allegorist in the Ancient Church. Surely if anyone would disavow a "literal narrative" of Genesis, it should be him, rather than the "more literal" Chrysostom of the Antiochene school.
Here are excerpts from Origen's homilies on Genesis:
(1) … According to the letter God calls both the light day and the darkness night. But let us see according to the spiritual meaning …
(11) “And God said, ‘Let the earth bring forth the living creature according to its kind, four-footed creatures and creeping creatures and beasts of the earth according to its kind.’ And so it was done. And God made the beasts of the earth according to their kind and all the creeping creatures of the earth according to their kind. And God saw that they were good.”
There is certainly no question about the literal meaning. For they are clearly said to have been created by God, whether animals or or four-footed creatures or beasts or serpents upon the earth. But it is not unprofitable to relate these words to those which we explained above in a spiritual sense.
(17) … The historical meaning, at least, of this sentence indicates clearly that originally God permitted the use of foods from vegetation, that is, vegetables and fruits of trees. But the opportunity of eating flesh is given to men later when a covenant was made with Noah after the flood. The reason for this, of course, will be explained more appropriately in their own places.
But allegorically the vegetation of the earth and its fruit which is granted to man for food can be understood of the bodily affections.
(Origen, Genesis Homily 1. Taken from The Fathers of the Church: A New Translation– Origen-Homilies on Genesis and Exodus)
As it can be seen, while Origen preached on and extolled the allegorical sense (no surprise), Origen did not discount the literal and historical sense of the Genesis Creation, but rather counts them as true realities which are however uninteresting. This is of course not to say that Origen is definitely orthodox in his view on creation, as he can be clearly in this homily (even without reading his book on creation) to believe in an eternal creation. However, Origen clearly thought that the literal or historical meaning of the Genesis text was true.
Of the Medieval Church, the fact of the matters is that they used the Quadriga as a hermeneutical tool. Certainly, there was more attention paid to the other three levels of meaning (the allegorical, anagogical, tropological), but the literal meaning was by no means discounted, especially since the text we are discussing has an obvious narrative layout.
It is therefore certainly most untrue that attention to the "literal narrative" is a legacy from the Enlightenment. Rather, such an hermeneutic can be already seen from the time of the early Church, and only gain prominence in the Enlightenment and post-Enlightenment Modernist and Postmodernist eras, as the truthfulness of the narrative events depicted in the Scripture come under attack. One can always quibble over the proportion of time and energy spent on the issue, but certainly if the attack is focused on that area, that is where our time and effort should be focused on too.