Wilson in his Works expressed a nuanced and often oddly interesting view on reason and revelation which points to his belief in theistic rationalism. While orthodox Christians believe the Bible is infallible and man's reason is subservient to revelation, and while strict deists believed all revelation is false and God revealed Himself only through nature discoverable by man's reason, theistic rationalists believed God revealed Himself primarily (not exclusively) through nature, not scripture, and as such only partially inspired the Bible. As Dr. Frazer put it in his seminal article on the subject, "revelation was designed to complement reason (not vice versa). Reason was the ultimate standard for learning and evaluating truth and for determining legitimate revelation from God."
What follows, some of Wilson's quotations that support theistic rationalism:
Wilson believed God revealed Himself through both nature and scripture. Wilson seemed to view both reason and revelation as, by themselves, incomplete, and put together largely complementary. From his Works, Volume I:
[H]ow shall we, in particular instances, learn the dictates of our duty, and make, with accuracy, the proper distinction between right and wrong; in other words, how shall we, in particular cases, discover the will of God? We discover it by our conscience, by our reason, and by the Holy Scriptures. The law of nature and the law of revelation are both divine: they flow, though in different channels, from the same adorable source. It is, indeed, preposterous to separate them from each other. The object of both is ― to discover the will of God ― and both are necessary for the accomplishment of that end.
However, as a theistic rationalist, he believes reason is primary:
[F]or obligation is nothing more than a restriction of liberty produced by reason. Reason, then, independent of law, is sufficient to impose some obligation on man, and to establish a system of morality and duty.82
Reason, say they, is the first rule of man, the first principle of morality, and the immediate cause of all primitive obligation. But man being necessarily dependent on his Creator, who has formed him with wisdom and design, and who, in creating him, has proposed some particular ends; the will of God is another rule of human actions, another principle of morality, obligation, and duty. On this distinction, the kinds of obligation, external and internal, are founded. These two principles must be united, in order to form a complete system of morality, really founded on the nature and state of man. As a rational being, he is subject to reason: as a creature of God, to his supreme will. Thus, reason and the divine will are perfectly reconciled, are naturally connected, and are strengthened by their junction.85
Wilson then notes why "reason" can establish law is because God has imbued man with a "moral sense."
This moral sense, from its very nature, is intended to regulate and control all our other powers. It governs our passions as well as our actions. Other principles may solicit and allure; but the conscience assumes authority, it must be obeyed. Of this dignity and commanding nature we are immediately conscious, as we are of the power itself. It estimates what it enjoins, not merely as superiour in degree, but as superiour likewise in kind, to what is recommended by our other perceptive powers. Without this controlling faculty, endowed as we are with such a variety of senses and interfering desires, we should appear a fabrick destitute of order but possessed of it, all our powers maybe harmonious and consistent; they may all combine in one uniform and regular direction.
In short; if we had not the faculty of perceiving certain things in conduct to be right, and others to be wrong; and of perceiving our obligation to do what is right, and not to do what is wrong; we should not be moral and accountable beings.
When Wilson discusses revelation, he makes clear Scripture's role is to support reason and conscience, not the other way around. The context makes clear that reason is primary, revelation secondary:
Reason and conscience can do much; but still they stand in need of support and assistance. They are useful and excellent monitors; but, at some times, their admonitions are not sufficiently clear; at other times, they are not sufficiently powerful; at all times, their influence is not sufficiently extensive. Great and sublime truths, indeed, would appear to a few; but the world, at large, would be dark and ignorant. The mass of mankind would resemble a chaos, in which a few sparks, that would diffuse a glimmering light, would serve only to show, in a more striking manner, the thick darkness with which they are surrounded. Their weakness is strengthened, their darkness is illuminated, their influence is enlarged by that heaven-descended science, which has brought life and immortality to light. In compassion to the imperfection of our internal powers, our all-gracious Creator, Preserver, and Ruler has been pleased to discover and enforce his laws, by a revelation given to us immediately and directly from himself. This revelation is contained in the holy scriptures. The moral precepts delivered in the sacred oracles form a part of the law of nature, are of the same origin, and of the same obligation, operating universally and perpetually.
Next, notice what Wilson earmarks as the revelation's most important teachings:
On some important subjects, those in particular, which relate to the Deity, to Providence, and to a future state, our natural knowledge is greatly improved, refined, and exalted by that which is revealed. On these subjects, one who has had the advantage of a common education in a christian country, knows more, and with more certainty, than was known by the wisest of the ancient philosophers.
Not things like the Trinity, Incarnation, Atonement or other creeds central to orthodox Christianity in which Wilson gives no indication that he believes; but rather "the Deity, to Providence, and to a future state," things first knowable from nature or reason, and which revelation's role is to "improve, refine, and exalt."
Interesting, Wilson next seems to almost elevate the scripture to a level of supremacy: "Thus it is with regard to reason, conscience, and the holy scriptures. Where the latter give instructions, those instructions are supereminently authentick."
But then claims scripture is deficient and repeats his assertion that scripture was not designed as God's primary revelation to man, but as a secondary revelation to man in what he already knows from reason and conscience:
But whoever expects to find, in [Scripture], particular directions for every moral doubt which arises, expects more than he will find. They generally presuppose a knowledge of the principles of morality; and are employed not so much in teaching new rules on this subject, as in enforcing the practice of those already known, by a greater certainty, and by new sanctions. They present the warmest recommendations and the strongest inducements in favour of virtue: they exhibit the most powerful dissuasives from vice. But the origin, the nature, and the extent of the several rights and duties they do not explain; nor do they specify in what instances one right or duty is entitled to preference over another. They are addressed to rational and moral agents, capable of previously knowing the rights of men, and the tendencies of actions; of approving what is good, and of disapproving what is evil.
Wilson then notes, reason and revelation largely operate together, but reason is supreme:
These considerations show, that the scriptures support, confirm, and corroborate, but do not supercede the operations of reason and the moral sense. The information with regard to our duties and obligations, drawn from these different sources, ought not to run in unconnected and diminished channels: it should flow in one united stream, which, by its combined force and just direction, will impel us uniformly and effectually towards our greatest good.
Finally, one reason I don't think Wilson believed the Bible infallible or inerrant is he then denies the possibility of miracles:
The law of nature is immutable; not by the effect of an arbitrary disposition, but because it has its foundation in the nature, constitution, and mutual relations of men and things. While these continue to be the same, it must continue to be the same also. This immutability of nature's laws has nothing in it repugnant to the supreme power of an all-perfect Being. Since he himself is the author of our constitution; he cannot but command or forbid such things as are necessarily agreeable or disagreeable to this very constitution. He is under the glorious necessity of not contradicting himself. This necessity, far from limiting or diminishing his perfections, adds to their external character, and points out their excellency.
Final final comment: Even though Wilson, like Blackstone whom he cites a few times in Works, tips his epistemological hat to scripture in a few places, Wilson and Blackstone hardly ever actually cite scripture in their works. For all of their dithering on reason and revelation and which is supposed to do what, the overwhelming majority of Wilson's and Blackstone's works are not the product of scripture, but rather, of reasoning.
As Gary North provocatively put it when talking about Blackstone in this regard:
[H]e then spent four volumes describing English common law with only a few footnote references to the Bible. In the first three volumes, running almost 500 pages each, each has one footnote reference to the Bible. The fourth volume, on criminal law(Public Wrongs), has ten references. Not one of them is taken by Blackstone as authoritative for civil law; they were seen merely as historical examples. There is not a single reference to “Bible,” “Moses,” or “Revelation” in the set’s index.
...Englishmen commonly tipped the brim of their epistemological caps to God and the Bible, but they did not take off their caps in the presence of God....It was considered sufficient for Blackstone to have formally equated biblical law with natural law. Having done so, he could then safely ignore biblical law.
This raises another question: Was Blackstone in fact deliberately lying? In a perceptive essay by David Berman, we learn of a strategy that had been in use for over a century: combating a position by supporting it with arguments that are so weak that they in fact prove the opposite....If he was not lying, then he was naive beyond description, for his lame defense of biblical revelation greatly assisted the political triumph of the enemies of Christianity in the American colonies.