Middleton is willing to make this the decisive gift, the one that people need to show or shut up about.
Middleton then goes on (p.123) and sees the loss of moral superiority and spiritual quality when the Church becomes part of the Roman Empire, but that's of course the Protestant strategy of dating the split, when the true light was lost, providing the target to which the Reformation can aim back.
The problem with the "popish legends", as Middleton called St Augustin's narration of miracles (p.140), was that they were on the verge of crossing over into reliques on the one hand (Middleton mentions St Steven) and had all the odium of this quintessential anti-Protestant issue as well.
Of course, the sources, e.g. Chrysostomos, were just as disappointed in some sense that the miracles had ceased, and were blaming lack of faith as the reasons---thence the claim about St Paul's handkerchief (p.131).
In general the Protestant criticism was, specifically mentioning Cardinal Robert Bellarmine (who was notorious to English Protestants due to his involvement in the Oath of Allegiance debate of James I), that once Christianity had become state religion, the Church would no longer pray for but curse the princes that were in her way (p.157).
Thus, Middleton can write (p.162), in good Protestant stance (though he is paraphrasing the Church fathers' position at that point):
The History of Gospel, I hope may be true, though the History of the Church be fabulous.The miracles are unhelpful because they take away from the the calm of the Christianity.
[The, RCK] ... sole tendency [of miracles, RCK] is to recommend, as a perfect pattern of the Christian life, the most extravagant enthusiasm and contemptible superstition, that any age or history perhaps has ever produced. (p.173)The story of the tongues cut out by the Arian princes from the confessors who can then still speak is scientifically relativized by the description of two cases where people, who were born without tongue or lost it due to small-pox induced ulcers, were yet able to speak (p.184f).
Yet the humble testimony of this single Physician, grounded on real experiment, will overturn at once all his pompous list of dignified authorities, and convince every man of judgement, that this pretended miracle, like all other fictions, which have been imposed upon the world, under that character, owed it’s [sic!] whole credit to our ignorance of the powers of nature. (p.185)