It is well known that C.S. Lewis borrowed the phrase “mere Christianity” from the seventeenth-century Puritan Richard Baxter; Lewis says as much in his book called–wait for it–Mere Christianity. Lewis also uses the phrase with some regularity in other writings, as indicated here. For instance, in his famous essay “On the Reading of Old Books,” which originally served as an introduction to a translation of Athanasius’ On the Incarnation, Lewis says:
In the same way sentences in a modern book which look quite ordinary may be directed at some other book; in this way you may be led to accept what you would have indignantly rejected if you knew its real significance. The only safety is to have a standard of plain, central Christianity (“mere Christianity” as Baxter called it) which puts the controversies of the moment in their proper perspective. Such a standard can be acquired only from the old books.
Lewis’ source in Baxter has also been known for some time (see link above): it comes from an introductory essay (“What History is Credible, and what not”) to his work Church-History of the Government of Bishops and Their Councils Abbreviated. I have transcribed the relevant passage below.
And now I must speak to the Accusers speeches of my self; I thank you Sir that you feigned no worse against me; if I am an Haeresiarcha, why would not you vouchsafe to name that Heresie which I have owned: I have given you large Field-room, in near 80 Books; and few men can so write, as that a willing man may not find some words which he is able to call Heresie: A little learning, wit, or honesty, will serve for such an hereticating presumption. I never heard that Arminius was called an Arminian, nor Luther a Lutheran, nor Bishop Laud a Laudian; but if you be upon the knack of making Names, you best know your ends, and best know how to fit them to it. But seriously, do you not know my Judgment? will not about 80 Books inform you? how then can I help it? No, but you know not what Party I am of, nor what to call me; I am sorrier for you in this than for my self; if you know not, I will tell you, I am a CHRISTIAN, a MEER CHRISTIAN, of no other Religion; and the Church that I am of is the Christian Church, and hath been visible wherever the Christian Religion and Church hath been visible: But must you know what Sect or Party I am of? I am against all Sects and dividing Parties: But if any will call Meer Christians by the name of a Party, because they take up with meer Christianity, Creed, and Scripture, and will not be of any dividing or contentious Sect, I am of that Party which is so against Parties: If the Name CHRISTIAN be not enough, call me a CATHOLICK CHRISTIAN; not as that word signifieth an hereticating majority of Bishops, but as it signifieth one that hath no Religion, but that which by Christ and the Apostles was left to the Catholick Church, or the Body of Jesus Christ on Earth.
And now Sir, I am sorry that you are not content with meer Christianity, and to be a Member of the Catholick Church, and hold the Communion of Saints, but that you must needs also be of a Sect, and have some other Name: And how shall I know that your Sect is better than another? Were not the Papists Sectaries and Schismaticks, damning most of Christs Body on Earth for not being subject to their Pope, I should not be so much against them. I find promises of Salvation in Scriptures to Believers, that is, Christians as such (if such sincerely,) but none of the salvation of men as Papists, Diocesans, Grecians, Nestorians, Eutychians, &c. I would say also [nor as Protestants] did I not take the Religion called Protestant (a Name which I am not fond of) to be nothing but simple Christianity, with opposition to Popery, and other such corruption. And now you know your own designs, your tongue is your own, and who can controul you, whatever you will call us; but I, and such others, call our selves MEER CHRISTIANS, or CATHOLICK CHRISTIANS, against all Sects and Sectarian names, and haters both of true Heresie, Schisme, and proud, unrighteous, hereticating and Anathametizing. Psal. 4. O ye sons of men, how long will ye turn my glory into shame? how long will ye love vanity, and seek after lying? But know that the Lord hath set apart him that is godly for himself: Psal. 12. 1, 2, 3, 4, 5. Help Lord, for the godly man ceaseth, for the faithful fail from among the children of men: They speak vanity every one with his Neighbour, &c. See the rest.
I will add, that if to be serious in the belief of the Christian Faith, and the Life to come, and in seeking it above this world, and in constant endeavours to please God, whoever be displeased by it, is it that maketh a man a Puritan, because he is not a formal Hypocrite, then I would I were worthy of the Titles which your Pseudo Tilenus and his Brother give me, who say, I am Purus Putus Puritanus,1 and one qui totum Puritanismum totus spirat:2 Alas I am not so good and happy. But Readers, when this sort of men have described the Puritans as the most intollerable Villains, you that knew them not may conclude, that they were men no more erroneous, or worse than I, how much better soever; for Bishop Morley saith of me, Ab uno disce omnes: And of my Doctrine, I have left the world a full account; and must shortly be accountable for it and my life to God, whose pardon and grace through Christ I daily beg and trust to.
There is so much (so much!) I’d like to discuss in this passage, but I shall restrain myself. So I’m not going to talk about the Very Important principles that are found in this short selection. I’m not going to talk about ecclesiology and sectarianism. I’m not even going to talk about whether Lewis and Baxter mean the same thing by the phrase (as has been done here).
No, I’m only going to talk about one narrow matter, but one that, if it is not noticed, can cause significant misunderstanding; and that is the meaning of the adjective “mere.” Nowadays, the phrase “mere Christianity” is likely to be interpreted as meaning “minimal Christianity” or “lowest-common-denominator Christianity.” But that is not what the term means. There is an older sense of the term (also noted here): “being nothing less than, absolute.” One finds it, for instance, in Shakespeare’s Othello II.2, where the Herald says:
It is Othello’s pleasure, our noble and valiant General, that upon certain tidings now arrived importing the mere perdition of the Turkish fleet, every man put himself into triumph….
In context, “mere perdition” means “absolute destruction.” This old sense, and not the modern sense, is the sense in which Baxter means it. As Timothy Miller has pointed out, “mere” doesn’t serve to indicate just another new descriptor in competition with many other such descriptors, but rather serves to point up Baxter’s desired absence of any qualifier whatsoever. He was making an anti-sectarian point, as if to say, “There is only the Christian faith, and a Christian is whoever believes in it. There are Christians and there are non-Christians, period. Away with party spirit of all kinds”: a 1 Corinthians sort of posture, as it were. This is what Baxter calls “Catholick Christianity.”
One can say more. The adjective “mere” is derived from the Latin adjective merus, “pure.” Baxter is surely thinking of this root when using the word. And because that is the case, one can detect a learned joke he is making. “Oh, you would like to call me a Puritan as a term of abuse? Ok, fine. I am, but not in the way you mean it. You say it as if I belonged to a party. I do not. I am only a ‘Puritan’ in this way: I claim to hold the mere (that is, pure) Christian faith, as a member of the catholic (that is, universal) church. And what makes it ‘catholic’ is the universality of this one, absolute, pure Christian faith. There is no other.”