The section is divided into two parts. While Part I provides an argument against believing in miracles in general, Part II gives four specific considerations against miracles based on particular facts about the world. Therefore, we may refer to the argument of Part I as Hume’s Categorical Argument against miracles and those of Part II as the four Evidential Arguments against miracles. Identifying Hume’s intentions with these arguments is notoriously difficult. Though the Evidential Arguments are fairly straightforward in and of themselves, there are two major interpretive puzzles: what the Categorical Argument of Part I is supposed to be, and how it fits with the Evidential Arguments of Part II. Some see the two parts as entirely separable, while others insist that they provide two parts of a cohesive whole.
The primary problem with this is that one interpretive option -- and I would argue the one that does far and away the best job at fitting the textual evidence -- is that Part I of ECHU X has no argument against believing on the basis of testimony that a miracle has happened. When Lorkowski later clarifies in a reconstruction he frames it this way:
Both testimonial probabilities supporting the occurrence of a miracle and (hypothetical) testimonial proofs supporting the occurrence of a miracle would be evidentially weaker than the proofs supporting the laws of nature. [Empirical Premise- EHU 10.2, EHU 10.13, EHU 10.36. The first clause is true by definition for probabilities, but Hume also establishes it more clearly in Part II.]
The basis for the premise shows precisely the problem. 10.36 (the numbers after the decimals are just the number of the paragraph) is very, very far into the argument of Part II. 10.2 is very naturally read as simply a brief summary of the entire essay. And the key passage, 10.13 does not give us a categorical conclusion:
And as a uniform experience amounts to a proof, there is here a direct and full proof, from the nature of the fact, against the existence of any miracle; nor can such a proof be destroyed, or the miracle rendered credible, but by an opposite proof, which is superior.
But, of course, Hume's account of 'proof' undeniably allows that we may have opposing proofs, and he is, in any case, hypothetically assuming that there is a testimonial proof for miracles. So all he actually concludes in Part I is that the proof for the law of nature and the proof for the miracle will balance against each other and the stronger proof (where 'stronger' here means more psychologically forceful) will win out, although diminished by the force of the opposition. This leads to the famous summing up of Part I, notably also conditional:
The plain consequence is (and it is a general maxim worthy of our attention), 'that no testimony is sufficient to establish a miracle, unless the testimony be of such a kind, that its falsehood would be more miraculous, than the fact, which it endeavors to establish; and even in that case there is a mutual destruction of arguments, and the superior only gives us an assurance suitable to that degree of force, which remains, after deducting the inferior.' When anyone tells me, that he saw a dead man restored to life, I immediately consider with myself, whether it be more probable, that this person should either deceive or be deceived, or that the fact, which he relates, should really have happened. I weigh the one miracle against the other; and according to the superiority, which I discover, I pronounce my decision, and always reject the greater miracle. If the falsehood of his testimony would be more miraculous, than the event which he relates; then, and not till then, can he pretend to command my belief or opinion.
And as Hume says at the beginning of Part II, he was assuming in Part I that it would be some kind of miracle for the testimonial proof for the miracle to be wrong -- or, at least, "a real prodigy" because it amounted to "an entire proof". He never, at any point, explicitly says that it would be less prodigious than the miracle itself; he only makes conditional claims. And then, of course, Part II is devoted to arguing that, in fact, when we are dealing with religious miracles, it would never be "a real prodigy" for the testimony to be wrong and thus that we never have "an entire proof" in any case.
Lorkowski's division of things seems to be a residue of the old interpretation that Part I has an 'in-principle' argument against believing in miracles on the basis of testimony. This has become more controversial, as I think may be indirectly recognized here, but the article really understates the extent of the controversy, since one may argue that Part I is entirely a set-up to Part II -- for which there is textual evidence -- and thus we aren't just dealing with different interpretations of what the argument against miracles in Part I is -- one may reasonably deny that there is any such argument. On such an interpretation, Hume is running a purely empiricist argument based on psychological claims about testimony; Part I merely sets the standard of evidence and Part II argues that religious miracles have never met it.