"Hold fast the form of sound words." -- 2 Tim. 1:13.
THIS second part of the Assembly's Shorter Catechism Explained, through various impediments, was not published, till about seven years after the first; which is the reason why there is an edition more of the first than of the second part.
In the Preface to the first part of this work, subscribed by the Rev. Mr. Ebenezer Erskine and me, the usefulness of sound standards of public authority, together with the divine warrant for such composures, is briefly set Forth; as likewise a short account of the method, which the Westminster Assembly most judiciously observe, in this compendious, and almost incomparable system of divinity, THE SHORTER CATECHISM.
Both these eminent lights, the Rev. Messrs. Ebenezer and Ralph Erskine, who assisted in composing and revising the first part of this Catechism, are some years ago removed to the upper sanctuary by death; the first soon after, and the second, a little before the publishing of it: so that the charge of this second part was, by a renewed recommendation of my brethren, laid upon me. They, indeed, promised to afford me materials, which some of them did; and I made all the use of them I could.
This performance, such as it is, was never judicially read and approved by any of our judicatories, (though several of my brethren had opportunity to peruse the most part of it, before the whole was issued;) therefore, any imperfections or weaknesses that may be found therein, are not to be imputed to the body of ministers, with whom I am, in providence, connected, but to myself only.
As to mistakes in divinity, I dare not say there are none; but, if there are, I may be confident to affirm, there were none designed.
In this edition, there are several questions added which were not in the former; particularly, on the ceremonial law, which was the typical gospel of the Jews; and others are altered and corrected, in the plainest way I could devise.
The words of the Shorter Catechism from which the explicatory questions are formed, are enclosed within brackets, as is done in the first part, to distinguish them from quotations out of the Confession and Larger Catechism, of which there are several, in both parts of this treatise: and the scripture proofs are now ranged in such an order, as the reader may see, at first view, the branch of the answer each of them is designed to confirm.
It has been acknowledged in all ages, that the catechetical way of instructing is the most speedy and successful method of conveying the knowledge of divine things; because thereby the truths of God are brought level to the weakest capacity, being separately proposed one after another, with plain and distinct answers to each. If people then would be at the pains carefully to peruse, particularly on Sabbath evenings, the helps that have been offered for understanding their Catechism, they would soon have the experience of attaining some tolerable insight into the leading principles of the Christian religion; and by that means hear the word preached with more spiritual benefit to their own souls; and likewise be capable to distinguish truth from error, in many of the practical books that are among their hands: for, the first principles of the oracles of God ought to be learned in the first place, and when the knowledge of these is once attained, a patent door will be opened to farther improvements; whereas, if the foundation is not laid, it is needless to dream of carrying up the fabric. And, indeed, herein lies the fatal mistake of the most part of people, that though they can scarce repeat, far less understand their Catechism, yet they imagine they may read any other divine subject that comes into their hands with advantage; while on the contrary, the understanding of their Catechism, in the first place, would be the most effectual and successful mean for their profiting by what they might read or hear, during the whole remainder of their life.
GLASGOW, May 3, 1765.
 The Rev. Mr. Ralph Erskine, minister of the gospel at Dunfermline, died Nov. 6th, 1752, in the 68th year of his age, and forty-second of his ministry in that place. He published several polemical treatises on various subjects; but his practical works, both in prose and verse, were first collected into two large folio volumes, and elegantly printed. They are now reprinted in ten handsome volumes octavo, with sundry additional sermons and discourses, not in the folio volumes; to which is prefixed an Account of the Author's Life and Writings; with an elegiac Poem on his death, not in the folio edition.