Discovery of the tunnel built by King Hezekiah to provide water to Jerusalem in time of siege (2 Kings 22:20 and 2 Chronicles 32:30), was confirmed by an accompanying inscription which dates to the reign of Hezekiah.
Minimalist scholars John Rogerson and Philip Davies claimed that the inscription does not date to the reign of Hezekiah, but to the Hasmonean era (less than two centuries before the birth of Christ), a claim used to cast doubt on the date of the tunnel itself, and to argue that it was not built by Hezekiah.
Although acknowledging that their view is contradicted by the unanimous consent of palaeographers,  Rogerson and Davies claim that palaeography is insufficiently precise to differentiate between 8th century and 2nd century texts. 
Ronald Hendel (a professional epigrapher specializing in Semitic languages), has responded strongly to the following claims made by Rogerson and Davies, demonstrating that they are in error.    
Frank Cross, (Professor of Hebrew and Other Oriental Languages at Harvard University), observed that Rogerson and Davies were unqualified to make judgments on the text. Professional epigraphist P. Kyle McCarter Jr made a similar statement.
André Lemaire (specializing in First Temple period Old Hebrew inscriptions), objected that Rogerson and Davies appeal to outdated scholarship.  Esther Eshel (renowned epigraphist), rejected the claim that palaeography was too imprecise to date the inscription reliably. 
Professor of Biblical Hebrew and Northwest Semitic epigraphy at Harvard University Jo Hackett made the same argument.  Avi Hurvitz (professor of Bible and Hebrew linguistics), observed that the claims of Rogerson and Davies had been rejected by the leading epigraphists, and disproved their linguistic arguments.  
Leading palaeographer Ada Yardeni dismissed the claim that the inscription shows evidence of a Hasmonean dating.
 ‘Discovered by some boys at play in 1880, the Siloam Inscription commemorates the dramatic meeting of two teams of tunnelers, digging from opposite directions, during the construction of the tunnel in the reign of Hezekiah. The text, written in paleo-Hebrew, offers an unusual contrast to the Biblical account (2 Kings 22:20 and 2 Chronicles 32:30). Like most ancient commemorative texts, the Biblical account gives the royal perspective, whereas the Siloam Inscription features the style and content of a man who witnessed and participated’, Parker, ‘Jerusalem’s Underground Water Systems Siloam Inscription Memorializes Engineering Achievement’, Biblical Archaeology Review (20.04.), 2004.
 The ‘minimalist’ view is that archaeology provides little or no support for the Biblical history, the ‘maximalist’ view is that archaeology overwhelmingly supports the Biblical history, and the moderate view is that archaeology substantially supports the Biblical history but that not all of it can be supported directly from archaeology.
 ‘They acknowledge that specialists in palaeography unanimously date the inscription to the last quarter of the eighth century BCE, but they maintain that the palaeographers are mistaken, apparently deluded by circular reasoning and professional hubris. This is a remarkable claim and deserves some consideration.’, Hendel, ‘The Date of the Siloam Inscription: A Rejoinder to Rogerson and Davies’, The Biblical Archaeologist (59.4.233), December 1996).
 ‘Rogerson and Davies’ chief contention is that palaeographic analysis of ancient Hebrew inscriptions is extremely imprecise. In the case of the Siloam Inscription, they write: “the fact is this: it is frequently not possible to prove on paleographical evidence alone whether a text in paleo-Hebrew dates from, say, the eighth-seventh centuries or is Hasmonean or later” (1996:146, italics in original).’, ibid., p. 233.
 ‘The inconclusiveness of the paleography is crucial to their larger argument that the Siloam Tunnel dates to the Hasmonean era.’, ibid., p. 233.
 ‘A review of the relevant evidence, however, shows that Rogerson and Davies’ paleographic arguments are deeply flawed. It is in fact quite easy to tell that the script of the Siloam Inscription belongs to the eighth-seventh century sequence and not to the paleo-Hebrew sequence of the Hasmonean era and later.’, ibid., p. 233.
 He rejects the clam that some of the letters in the text have no parallels in Iron Age inscriptions, casting doubt on the idea that they were written during the Iron Age; ‘The problem with this statement is that there are plenty of parallels to these four letters in Hebrew inscriptions from the late Iron Age, a number of which are datable by their archaeological context’, ibid., pp. 233-235.
 He rejects the claim that the script of the Siloam Inscription is closest to 4QpaleoExodm, one of the Dead Sea Scroll texts, dating to the first century; ‘In addition to the differences in zwaw, yod, kap, and qop, there are noticeable differences in dalet, lamed, mem, ‘ayin, and pe. Several other letters have more subtle differences in length, proportion, or stance. The reason for these differences in script is easy to ascertain: the letters in 4QpaleoExodm belong to a different (and later) stage in the historical development of Hebrew script than the letters in the Siloam Inscription. The paleo-Hebrew scripts of the Hasmonean era and later have undergone noticeable development in comparison to the scripts of the eighth-seventh century BCE.’, ibid., pp. 235-236, ‘I have gathered five instances of this sequence from inscriptions from the eighth-seventh century 3CE and one instance from 4QpaleoExodm (see chart on facing page). It is quite easy to see that the 4Q script is the odd one out and clearly differs from the eighth-seventh century BCE scripts. In contrast, the Siloam Inscription clearly belongs in the company of the other eighth-seventh century BCE inscriptions.’, ibid., p. 236.
 He rejects the claim that some linguistic features of the text are incongruous with an Iron Age date; ‘It is worth noting that Rogerson and Davies’ linguistic comments on Siloam inscriptions are also unwarranted. They state that “some of the linguistic features of the Siloam Inscription become problematic if it is early” (1996:146). These features are the apparent internal matres in lilwd and int’s.’ and the pronominal suffix of til, (where one would expect a final he). These forms are easily comprehended by the following observations. 1) lblwd and niiw’s may be consonantal spellings with the dipthong Iwl (so Cross and Freedman 1952:50-51), or they may be early examples of internal matres in the Siloam inscription, as found sporadically in other eighth century BCE inscriptions (Royal Steward, some Ihlk seals, etc.; see Sarfatti 1982:58-63).’, ibid., p. 236.
 ‘The list of significant features differentiating Old Hebrew from paleo-Hebrew can be extended to most, if not all, letters of the alphabet. To identify them requires an eye and memory for form, gifts that make the paleographer. Without such gifts, a scholar is in the same straits as the tone-deaf musician who wishes to conduct an orchestra.’, Cross, ‘Because They Can’t See a Difference, They Assert No One Can’, Biblical Archaeology Review (23.02.), 1997.
 ‘No epigraphist trained in the scripts of these periods would confuse second-century B.C.E. paleo-Hebrew with sixth-century B.C.E. Hebrew, much less with eighth-century B.C.E. Hebrew.’, McCarter Jr, ‘No Trained Epigraphist Would Confuse the Two’, Biblical Archaeology Review (23.02.), 1997.
 ‘Because all Hebrew epigraphers now date the Siloam Inscription to the eighth century B.C.E., Rogerson and Davies are obliged to go back nearly a century for authority.† Of course, this earlier generation of scholars could not have been aware of the numerous Hebrew inscriptions from the First Temple period discovered since then.’, Lemaire, ‘Are We Prepared to Raze the Edifice?’, Biblical Archaeology Review (23.02.), 1997.
 ‘These examples, as well as many others, show that paleography stands on a strong and stable foundation. Today paleography can date documents to within half a century. It is true that paleography alone can only tell us that the Siloam Inscription may have been written at the end of the eighth century or in the seventh century B.C.E.,† but paleography can tell us with certainty that the inscription was not written in the second century B.C.E., as Rogerson and Davies “strongly suggest.”.’, Eshel, ‘Some Paleographic Success Stories’, Biblical Archaeology Review (23.02.), 1997.
 ‘Rogerson and Davies’s argument assumes that paleographers (neither Rogerson nor Davies is known as a paleographer) cannot tell the difference between pre-Exilic Old Hebrew and post-Exilic archaizing paleo-Hebrew. But they are wrong—very wrong. The science of paleography—the dating of scripts by the shape, form, stance, stroke order, and direction, as well as by other telltale diagnostic indications—can now date these scripts within a century and sometimes even closer. Contrary to Rogerson and Davies, paleographers can distinguish between pre-Exilic Old Hebrew and post-Exilic paleo-Hebrew. Rogerson and Davies admit, in fact, that the Siloam Inscription’s waw, yod, kap and qop do not fit well into a second-century B.C.E. script chart, and this should have been enough to tip them off to the problem with their argument.’, Hackett, ‘Spelling Differences and Letter Shapes Are Telltale Signs’, Biblical Archaeology Review (23.02.), 1997.
 ‘I am not surprised that some of the leading paleographical authorities in our field have so severely criticized the effort of Rogerson and Davies to place the Siloam Inscription in the Hasmonean period.’, Hurvitz, ‘Philology Recapitulates Paleography’, Biblical Archaeology Review (23.02.), 1997.
 ‘The Hebrew of the Siloam Inscription is worlds apart from the Hebrew of the Dead Sea Scrolls or the Hebrew of the apocryphal book known as Ben Sira (also known as Ecclesiasticus or “The Wisdom of Jesus, Son of Sira”). To anyone versed in Hebrew linguistics, the Siloam Inscription clearly does fall under the heading of classical Hebrew, as manifested in classical Biblical literature.† It is true that the linguistic tools at our disposal cannot tell us whether the Siloam Inscription specifically reflects the time of Hezekiah’s rule (727–698 B.C.E.). On the basis of both the Biblical and post-Biblical evidence, however, we can conclude that—linguistically—the inscription must be dated to the classical phase of ancient Hebrew, that is, to the pre-Exilic period (before 586 B.C.E.).’, ibid.
 ‘Secondly, they argue that “the Chronicler’s Hebrew can mean that Hezekiah closed off the pool formed by the spring” (italics added). This is, indeed, a surprising suggestion. It cannot be admitted in a serious philological discussion. It is simply not what the Hebrew text says. To use Rogerson and Davies’s own wording, this suggestion is at best a “paraphrastic translation.” Worse, their suggestion violates a basic methodological ground-rule of any philological analysis: that the outcome of that analysis should not be inferred from—let alone dictated by—considerations lying outside the domain of philology.’, ibid.
 ‘In sum, it is the Biblical and inscriptional evidence adduced by Rogerson and Davies in support of their claim that undermines it. I would strongly suggest, therefore, that if they insist on their theory regarding the late dating of the Siloam tunnel, they should drop the linguistic argumentation from their discussion—which for them is unfamiliar territory.’, ibid.
 ‘If the Siloam Inscription were inscribed in the Hasmonean period, its script would reveal a late stage of evolution (like the paleo-Hebrew scrolls) or artificial archaized characteristics (like the Hasmonean coins). It displays neither.’, Yardeni, ‘They Would Change the Dates of Clearly Stratified Inscriptions—Impossible!’, Biblical Archaeology Review (23.02.), 1997.