Connected to a previous question on the matter, the non-Muslim says that literature, by its very nature, can never be taken as a yardstick for miraculous Divine interventions into human history, since there is so little of literature that has been uncovered, so much speech goes unnoticed and uncategorized, and it might be possible that some of these tracts of poetry, essays, prose, etc. are in fact greater than the Qur’an, but that they have simply remained concealed. What is our response to this claim?

Answered by Sharif Randhawa (Researcher at Bayyinah Institute, owner of Qur’anic Musings blog), with slight modifications and an additional note

This claim basically amounts to saying that if no extant literature or contemporary authors are able to meet the Qur’an’s challenge, well then there might be some secret long-lost work of literature that no one knows of that is far superior to anything in written record, or that an amazing speech (miraculous in all but name) was thought out but that it was eventually not delivered, or some other similar scenarios.  From what I can see, this is a very farfetched conjecture that merits little attention.

[Note: The challenge of the Qur’an is to actually bring forth, into the public, something of similar or greater value than the Qur’an, not simply make the claim that something might exist which has yet to be found, or that it exists in the mind of the speaker but has yet to be delivered. Thus, if the opponent says that a lost tract may exist which is superior to the Qur’an, it is from the very nature of evidence-gathering that no consideration can be given to this tract until it is brought out into the open.

Concerning extant literature or speech that is uncategorized, this is again an “appeal to the unknown”. First, the purported categorization must take place based on acceptable standards, and only then a hypothetical comparison with the Qur’an, in the various aspects of its inimitability, can be carried out. And this is in fact one of the challenges of the Qur’an, that any literature or speech that one may find or come up with can eventually be placed into a category along with other types of humanly produced literature, while this is not the case with the Qur’an, especially when all aspects of this revelation are considered as a whole].