Francis Turretin discusses the importance of identifying the true visible church by examining its marks, particularly focusing on the truth of doctrine and its conformity with the word of God through pure preaching and lawful administration of sacraments. He emphasizes the necessity of distinguishing the genuine society of pious Christians from heretical groups, highlighting the significance of joining a church that upholds the true teachings of Scripture for salvation. Turretin explains that the marks of the church, such as the preaching of the word and the administration of sacraments, are essential for recognizing the true church and avoiding false assemblies. He argues that the church's purity in doctrine and worship, rooted in Scripture, is a fundamental criterion for discerning the true church from heretical congregations.

Twelfth question; the marks of the church - Is the truth of doctrine which is held in any assembly, or its conformity with the word of God by the pure preaching and profession of the word, and the lawful administration and use of the sacraments, a mark of the true visible church? We affirm against the Romanists. I. After having treated of the nature, properties and adjuncts of the church, the order demands that we discuss its marks. This question pertains to its exter­nal state and is of the highest importance in religion. For since salvation cannot be obtained except in communion with the true church and many glory in this sacred name who are destitute of its truth, it is of great value to know its true marks that we may be able to distinguish the true fold of Christ from the dens of wolves; and the genuine society of pious Christians (to whose communion we are called) from the conventicles of heretics, which must be shunned by us; also that thus we may know what that assembly is to which it is necessary that we should join ourselves that we may obtain salvation. And because the question can be twofold (the first concerning the true marks, which are asserted by us; the other concerning the false and adulterous which are obtruded by the Romanists), we will discuss each separately and now treat of the first. II. By marks, however, are commonly understood certain external signs striking the senses by which we arrive at the knowledge of a hidden thing, which are called by the Greeks gnorismata. Now these are either only probable and verisimilar (which are called eikota), of which this is the nature—that they in some measure designate by a probable but least necessary reason a thing; to wit, those which are drawn from external and accidental adjuncts which clothe and attend the thing itself. Others are necessary and essential (which are called tekmeria, which indicate the thing investigated certainly and infallibly: as smoke, fire; respira­tion, life; because they are taken from the essence of the thing or from its inseparable properties). Now we do not here treat of marks of the first order, but of the latter. III. For the truth of a mark, various persons require various things. Some re­quire that it be essential, not accidental; proper and not common; certain, clear and sensible, not doubtful and unevident. Others (as Bellarmine) require that it be proper, somewhat known and inseparable. We think only two are required, to which the others are easily referred—that it be proper and that it be somewhat known. For if it is proper, it is also necessary, essential and inseparable; if some­what known, it is evident and sensible. IV. (1) As the church can-be viewed either as to internal and mystical state and as invisible, or as to external state and as visible and instituted, it can be disputed in different ways about its marks. Either inasmuch as it is invisible for recognizing the true elect and believers, in which sense it has for marks faith, hope and love put on by efficacious calling, from which each one is certain of his own calling (2 Pet. 1:10) and by which he renders it at least probably certain to others (Mt. 5:16; Jam. 2:18). But we do not treat of these marks here. Or inasmuch as it is visible and according to the form of collection and external union. Thus concerning its marks, it is inquired what are the marks and characters by which the true visible church (to which believers ought to join themselves for salva­tion) can be known. V. (2) The question does not concern the marks of the Christian church in general; for the profession of Christianity sufficiently distinguishes this from the heathen and other unbelievers. But it is treated in particular of the marks of a particular visible church that we may distinguish an orthodox and purer church from a heterodox and heretical; so that this being found wanting, we may betake ourselves to the communion of that. Thus a twofold confederation of Christians must be distinguished here. One general, founded upon the profession of Christi­anity and contained in the Apostles' Creed and baptism as marks of Christianity, which indeed can suffice to constitute a baptized Christian, but certainly not to the obtaining of salvation; since it is often exposed to various fundamental er­rors, in faith as well as in worship. The other special, in a communion which has the purity of the word and the sacraments, mingled with no heresy and idolatry, in which salvation can be obtained (concerning which we properly treat here). Not in what manner a society of Christians can be distinguished from an assem­bly of pagans, Turks and other unbelievers; but how of the various assemblies which profess the name of Christ, the true and orthodox can be distinguished from the false and heretical, which are unworthy of the name of the true church. VI. Now although in assigning the marks of the true church, a certain diversity in words occurs among the orthodox, still they agree in the thing itself. For whether it is called one alone (to wit, the truth of doctrine and conformity with the word of God) or many (to wit, the pure preaching of the word with the lawful adminis­tration of the sacraments, to which some add the exercise of discipline and holi­ness of life or obedience given to the word), it is all the same thing. For where the truth obtains publicly, there also love and holiness nourish in their own way; nor can the pure word of God be preached anywhere without the sacraments being also administered lawfully in the same place and the discipline prescribed in the word of God being observed and thriving, since these two flow from the word of God and are appendages of it. VII. Further we must observe about these marks: (1) That there are different degrees of necessity and some are more necessary than others. In the first degree of necessity is the pure preaching and profession of the word, since without it the church cannot exist. But the administration of the sacraments does not have an equal degree of necessity which so depends upon the former that it may nevertheless be wanting for a time (as was the case with the Israelite church in the desert, which was without circumcision). The same is the case with discipline, which pertains to the defense of the church, but which, being removed or corrupted, the church is not immediately taken away. (2) There is a certain latitude of these marks as they admit various degrees of purity—now more perfect, then more imperfect, as they more or less approach to the rule of Scripture (hence they argue a church either purer or impurer. But not on this account is this latitude to be extended so far as that fundamental errors should be tolerated, but only faults and lighter errors. As therefore that society cannot retain the name of a true church which cherishes capital errors overturning the foundation of salva­tion, so it does not straightway lose the name of a true church which impinges anywhere upon doctrine. And although it can no longer be called a pure church, still it does not cease to be a true church. Hay and stubble do not immediately take away the dignity of a church from any assembly, provided it is not built upon them as a foundation, according to the rule of the apostle (1 Cor. 3:12). (3) The church can be viewed either as constituted or as to be constituted; either in a pure and uncorrupted state or in an impure and partly corrupt state. The ques­tion is here instituted concerning its marks—with respect to the former and not the latter state. (4) The opinion of the church is not to be estimated from the private opinions of rulers and bishops who, seized with a frenzy for disputes, often pass over to steep places, which nevertheless are either not understood or are not approved by the church. Rather the opinion of the church is to be esti­mated from the doctrine and practice publicly received and retained. VIII. Since the truth and conformity of doctrine with the word of God or the sincere preaching and observance of the gospel are said to be the proper marks for distinguishing the church, others are not excluded, but included. For whether or not you attend to the voice of God, it is the word; or the faith of men, it is about the word; or life and obedience, it is the fruit of the word; or good order (eutaxian), it is from the word; or the sacraments, they are seals and appendages of the word, and the word visible. And thus wherever we turn our eyes, the divine word is a true criterion (feriterion) of the church, which on that account is said to be a standard, scepter, light, rule and balance by whose polar star and rule all things must be examined. However, a mark can be spoken of in two ways: either with respect to the efficient cause (to wit, God, who uses it to sealing the true church); or with respect to the receiving subject (when received by the hearers it brings forth the fruits of faith and piety, from which it is known). IX. It is proved that this is a true and essential mark of the church. (1) From Scripture, which by this sign distinguishes true Christians as members of the church from false: "My sheep hear my voice and follow me" (Jn. 10:27). Here Christ proves that the unbelieving Jews are not of his fold (i.e., do not belong to the true church) be­cause they do not hear the voice of the shepherd. "Ye are not of my sheep, as I said unto you" (this reason being added), because "my sheep hear my voice" (v. 27). As therefore they who do not hear the voice of Christ are not of his fold, so on the opposite, they who hear and follow him truly belong to it and are mem­bers of him. However, what is the case with individuals, the same ought to be the case with the whole church, which is gathered together from individuals. Nor ought it to be objected here: (a) "that the mark of the sheep is set forth, not of the church, and it is taught who are the elect, and not where the church is." Both are necessarily contained here. For the sheep of Christ cannot be known or who the elect are without the church being known from this very thing (which consists of sheep and the elect) and where it is. For if the church is a flock of sheep and the sheep are no other than they who hear the voice of Christ, wherever the voice of Christ is heard, there the sheep of Christ (and so the true church) must necessarily be. (b) "It cannot be a sensible mark because that hearing, to be true, ought to be of the heart, not of the body." That hearing ought so to be made with the heart that it should also exert itself outwardly, both by external docility and a profession of the word and by a real obedience to a following of Christ. Now although this docility with respect to others does not produce an infallible certainty, but only a moral certainty from the judgment of charity (because it cannot make us certain of its sincerity), still it forms an indubitable argument both with respect to individuals (because he who is persuaded that he hears the voice of Christ, by that very thing knows that he is a disciple of Christ and a member of the church); and with respect to the whole assembly (because where the voice of Christ sounds and is heard, there the true church cannot but be). X. (2) To the same belongs what Christ says, "If ye continue in my word, then are ye my disciples indeed; and ye shall know the truth, and the truth shall make you free" (Jn. 8:31, 32); "He that is of God heareth God's words" (v. 47); "If a man love me, he will keep my words: and my Father will love him, and we will come unto him, and make our abode with him" (Jn. 14:23). Here the keeping of the word of Christ and his precepts is set forth as a mark of his true disciples and as the means of obtaining his presence in the midst of them. However, where Christ dwells with the Father, there it cannot be denied that the true church is, since it is his house and temple. This is confirmed from Mt. 18:20, where Christ promises his presence in the midst of those who are gathered together in his name. For since the saving presence of Christ has place in the true church alone and it is promised to those who are gathered together in the name of Christ (i.e., who assemble by his authority to preach and hear his word), that is undoubtedly the true church where believers come together in the name of Christ. Nor can it be said that "it is demonstrated from this passage where Christ is, but not where the church is." Christ cannot be found without his church also being found (in which he dwells and which is his body, which cannot be separated from him). XI. (3) The same thing is proved from Acts 2:42, where the mark of the apostolic church is set forth by a perseverance in the doctrine of the apostles, by communion and the breaking of bread. "The disciples continued steadfastly in the apostles' doctrine and fellowship, and in breaking of bread, and in prayers." Thus the pious exercises of the primitive church are pointed out, which are so many marks of it, by which the church of Christ was distinguished a posteriori from the Jewish synagogue and other assemblies of unbelievers. However, three things are men­tioned as the principal: preaching and hearing of the word, prayers and the par­taking of the Lord's Supper (described synecdochically by "the breaking of bread," as in Acts 20:7). And thus "fellowship and breaking" (koinonia kai te Uosei) is put by hendiadys for "fellowship of breaking" (fcoinonia te5 klaseos} (as in Virgil, "we make a libation with bowls and gold," Georgics 2.192 [Loeb, 1:128-29], i.e., with golden bowls). As therefore the apostolic church was discerned by these signs (gnorismasi), by the same it ought to be known at this day. Therefore wherever the doctrine of the apostles and the legitimate use of the sacraments and of prayers are, there the true church of Christ certainly is. XII. (4) Because there ought to be some method for distinguishing a true church from a false, as for distinguishing a false church from a true, and false prophets from true teachers. Now this is no other than falsity of doctrine and its disagreement with the word of God (Is. 8:20; Dt. 13:1, 2; Lk. 16:29). Hence, Christ (speaking of the false prophets) says, "By their fruits ye shall know them" (Mt. 7:16); not only as to morals and life, but especially as to doctrine (as is gathered from Lk. 6:45). And John wishes the spirits (i.e., the teachers) to be tried, whether they are of God (1 Jn. 4:1). If you seek the rule of trying, he brings it forward in the following verses from the truth of doctrine: "Hereby know ye the Spirit of God: every spirit that confesseth that Jesus Christ is come in the flesh is of God; and every spirit that confesseth not that Jesus Christ is come in the flesh is not of God" (vv. 2, 3). And more clearly in the second epistle, "Whosoever transgresseth, and abideth not in the doctrine of Christ, hath not God. He that abideth in the doctrine of Christ, he hath both the Father and the Son" (2 Jn. 9); "If there come any unto you, and bring not this doctrine, receive him not into your house" (2 Jn. 10). Paul confirms this when he denounces an anathema upon him who wished to preach another gospel than what had been preached: "If I, or an angel from heaven, preach any other gospel unto you than that which we have preached unto you, let him be accursed" (Gal. 1:8). He not only wishes to be rejected whatever would be foreign to the gospel, but that an anathema should be denounced upon him who should dare to introduce it into the midst of them, whoever he might be, whether an apostle on earth or even an angel from heaven (by whom after Christ nothing more illustrious and more to be revered can be granted). Thus Paul excludes the most specious marks of au­thority and the greatest miracles which can be obtruded (such as the descent of an angel from heaven). Now if the presence of an angel or the authority of an apostle cannot secure faith from us (if it is opposed to the gospel), how much more ineffectual will that authority be which a local or personal succession can conciliate, since such successors cannot be reckoned greater than the apostles? Again, if the apostles wished the doctrine of the gospel to be the rule by which true or false teachers are known, how much more today when nothing infallible remains to us except the Scriptures? XIII. (5) Because what always belongs to the church alone and as a whole ought to be an essential and specific mark of it, by which it is discerned from all these assemblies, not only of unbelievers, but also of heretics. And yet the truth of doctrine, which shines forth in the preaching of the word and administration of the sacraments, is such. For the church alone is the house of God, the pillar and ground of the truth (1 Tim. 3:15). Alone, built upon the foundation of the apos­tles and prophets (Eph. 2:19, 20); alone has the seal of the covenant (Mt. 28:20; 26:28; Acts 2:42; Gen. 17); alone possesses the word and by it is distinguished from other assemblies (Ps. 147:19; Dt. 4:6). Nor do these privileges belong to it for a time, but always and forever even unto the consummation of ages (Eph. 4:11, 12). Thus it is well gathered hence, that where the preaching of the word and the administration of the sacraments are, there the church is; and in turn, where the church is, there is the preaching of the word and the administration of the sacraments. XIV. (6) That by which the visible church is constituted, congregated and conserved, so that, it being posited, the church is posited, it being removed, the church is removed, that also is its proper and essential mark. For no mark is more certain than that which is drawn from its cause and inseparable property. Now such is the preached and received word (1 Cor. 4:15; Eph. 2:19, 20; 5:26; 1 Pet. 1:23; Jam. 1:18; Mt. 28:19, 20), which constitutes, conserves and nourishes the church so that, it being posited, the church is posited, and it being removed, the church is removed. Hence the removal of the candlestick or the ministry of the word draws after it the destruction of the church (Rev. 2:5); and the ceasing of proph­ecy implies the scattering of the people: "Where there is no vision, the people perish" (Prov. 29:18). XV. (7) The fathers agree with us. Tertullian: "That must undoubtedly be re­tained which the church received from the apostles, the apostles from Christ, and Christ from God" (Prescription Against Heretics 21 [ANF 3:252; PL 2.33]). And speaking of heretics: "Their very doctrine compared with the apostolic from its diversity and contrariety will pronounce that neither was an apostle its author, nor an apostolic person" (ibid., 32 [ANF 3:258; PL 2.45]). And he intro­duces the church speaking thus: "I am the heir of the apostles; as they provided in their will, as they committed it to faith, so I hold it" (ibid., 37 [ANF 3:261; PL 2.51]). And afterwards: "Whence, however, are heretics extraneous and enemies to the apostles unless from diversity of doctrine, which each one according to his will either brings forward or receives against the apostles?" (ibid.). Chrysostom says, "A Gentile comes and says, I wish to become a Christian, but I know not to whom to join myself. There are among you many contentions, seditions and tumults, I know not what dogma to select, what to prefer. Individuals say, I speak the truth, I know not which to believe, since I am ignorant of the Scriptures, and they cover over both the same, indeed this is much for us. For if we should say we believe reasons, deservedly would you be disturbed; but since we receive the Scriptures, these are simple and true, it would be easy for you to judge—if anyone agrees with them, he is a Christian, if anyone fights against them, he is far from this rule" ("Homily 33," Acts of the Apostles [NPNF1,11:210-11; PG 60.243-44]). "Where faith is, there is the church; where faith is not, there the church is not" (Chrysostom, "Homilia sexta," Opus imperfectum: eruditi commentarii in evangelium Matthaei [PG 56.673]). "When heresy, which is the army of Antichrist, obtains, there is no proof of the church, except only by the Scriptures" (Chrysostom, "Homilia 49*," Opus imperfectum in Matthaeum [PG 56.908-9]). The author of the commentary on the Psalms under the name of Jerome on Psalm 133: "The church does not consist in walls, but in the truth of doctrines. The church is there, where true faith is. But fifteen or twenty years before, all these walls of the churches here held heretics. The church, however, was there, where true faith was" (Breviarium in Psalmos [PL 26.1296] on Ps. 133). Ambrose: "The faith there­fore of a church especially is commanded to be sought, in which if Christ is a dweller, it is undoubtedly to be chosen, but if the people are faithless or a heretical teacher deforms the dwelling, the communion of heretics is to be avoided, it is to be considered a synagogue to be shunned" (Expositions in LMcam 6.68 [PL 15.1772] on Lk. 9:5). Augustine: "Let us not hear, I say this, you say that; but let us hear, the Lord says this. There are indeed Dominical books, in whose authority we both agree, we both believe, we both observe. There let us seek the church; there let us decide our cause" (Contra Donatistas: De Unitate Ecclesiae 3.5 [PL 43.394]). "I have the most manifest voice of my pastor commending to me, and without any hesitation setting forth the church, I will impute it to myself, if I shall wish to be seduced by the words of men and to wander from his flock, which is the church itself, since he specially admonished me saying, my sheep hear my voice and follow me; listen to his voice clear and open and heard; who does not follow him, how will he dare to call himself his sheep?" (ibid., II*.28 [PL 43.410]). "To salvation itself and eternal life no one comes, except him who has the Head, Christ. No one, however, could have the Head, Christ, except him who was in his body, which is the church, which we ought to recognize as the head itself in the sacred canonical Scriptures; not to seek it in the various rumors and opinions of men, and in their deeds and words. Let them demonstrate their church if they can, not in the discourses and rumors of Africans, not in the councils of their bishops, not in the writings of any disputants, not in deceitful signs and wonders. But in the prescription of the law, in the predictions of the prophets, in the singing of Psalms, in the words of the shepherd himself, in the preaching of the evangelists, i.e., in all the canonical authorities of the sacred books" (ibid,, 18* .47 [PL 43.427-28]). "The question between us and the Donatists is, where is the church? What, therefore, are we to do? Are we to seek it in our words or in the words of its Head, our Lord Jesus Christ? I think we ought the rather to seek it in the words of him who is the truth and best knows his own body" (ibid., 2.2 [PL 43.392]). Many such things proving our point are to be found in the same place which we omit for the sake of brevity. "In the Scriptures we have learned Christ, in the Scriptures we have learned the church, we have these Scriptures in common, why shall we not retain both Christ and the church in them?" (Letter 105, "To the Donatists" [FC 18:206; PL 33.401]). Vincent of Lerins, as Sixtus Senensis observes, lays down the authority of the Scriptures as the first rule of discerning a true church from a heretical church (Bibliotheca sancta 6, annot. 104 [1575 ], 2:153). XVI. (8) Not a few Romanists are on our side here. Bellarmine places holiness of doctrine among the marks of the church and defines it "by a profession of the same Christian faith and participation of the same sacraments" ("De Ecclesia Militante," 3.2 Opera [1857], 2:75). Elsewhere, he concedes, "When the Scrip­ture is received and speaks clearly, and the question about the church arises, then the church can be judged from the Scriptures as better known" ("De Notis Ecclesia," 4.2* Opera [1857], 2:108). Thus, while he answers to the dicta of Augustine (in which he affirms that the church ought to be demonstrated from the Scrip­tures), he confesses that "the Scriptures teach, what are the marks of the church" ("De Notis Ecclesia," 4.2 Opera [1857], 2:108). Hence no less evidently than necessarily, it follows that the Scripture is not only a mark of the church, but also the principal and primary of all marks, since from it and by it its remaining marks are known. Driedo: "The church is to be known and sought from the Scriptures" ("De ecclesiasticis scripturis et dogmatibus," 4.4 Opera [1572], 1:239). Cassander acknowledges that "the marks of the church are the doctrine of the gospel and the use of the sacraments" ("De Articularis Religionis…consultatio," Art. 7 in Gerogii Cassandri…Opera [1616], p. 927). Stapleton says, "The preaching of the gospel is the proper and very prominent mark of the Catholic church" ("De Principiis Fidei," 1.22 Opera [1620], 1:25). He also grants that "the church of Christ is known to the wise and spiritual by sound doctrine and the right use of the sacraments" ("Relectionis Principiorum Fidei," I, Q. 4, Art. 5 Opera [1620], 1:577). Gregory de Valentia says, "We confess that the church of Christ can be with­out neither truth of doctrine, nor the legitimate use of the sacraments and of those with whom these are altogether retained, the true church consists" (Commentariorwn theologicorum, Disp. I, Q. 1, Punct. 7.18 [1603-1609], 3:148). Others also confess the same thing. XVII. It is one thing to ascribe the marks of the church falsely to themselves and to boast of them; another to, possess them truly. That is of fact; this is of right. The false boasting of heretics claiming the marks for their assembly ought not to prejudice the certain persuasion of believers because we must judge of marks not from the dreams of the sick or the opinion of the proud, but from the truth of the thing. No more can it be said that our marks are not proper, but common because heretics (even schismatics) ascribe them to them­selves: (1) than if one should say the covenant of God is common to the rescinded and cut off Jews with the Christians because they boast of it; or that the justice of a cause belongs as well to the plaintiff as to the defendant because both claim it. (2) Ad hominem for the same reason, the marks of the Romanists will have to be rejected because not a few besides them ascribe them to themselves (as antiquity, unity, holiness of doctrine and other things of this kind). (3) Nay, no marks of anything in the world can be granted which some impudent and mendacious sophist will not claim for himself. Who is ignorant that the Devil wishes to hold himself as God; that the prince of darkness transforms himself into an angel of light, Antichrist, to arrogate to himself the name of Christ; and the harlot, to conceal herself under the habit of a matron. XVIII. It is one thing to know who are the elect singly; another to know where they are and in what assembly they may be found. Our marks do not go so far as to manifest the former to us, but only the latter (which is sufficient that we may ascertain to what assembly we ought to join ourselves). As in the state, it is not necessary to know distinctly and certainly who are true and faithful citizens, who obey the laws heartily; it is sufficient for us to know what is the republic in which such laws flourish. XIX. Although the pure preaching of the word does not always prevail in the church, it does not follow that this mark is separable from the church and that it is therefore falsely said to be a mark. That purity ought to be understood with a certain latitude, nor does the church at once cease when the purity ceases according to some degrees, provided it does not cease altogether. Purity ought to be in fundamentals in order that it may be a true church, although in other respects various errors can obtain in it from which it could contract various degrees of impurity (which although they take away from it the name of a pure church, still they do not remove the name of a true church, as long as the foun­dation remains safe and unimpaired). The pure preaching of the word and the purity of the church walk hand in hand. If the former is in every part pure and free from error, the latter also will be pure; but if the church begins to be corrupt it does not at once cease to be a true church until the foundation is assailed. XX. Although the dispensation of the word and sacraments are good and gifts to the church, still they are no less its marks since the one is not opposed to the other: as in earthly things, possession and use of these is the mark of a transferred ownership, nor moreover does it cease to be a fruit or a good. Thus the word is a mark of the covenant made by God with the church (as its authentic instrument, sealed with the seals of the sacraments, from the lawful dispensation of which the richest fruits redound to the possessors). XXI. Better known by nature is one thing; better known by us is another. Scripture is better known by nature than the church because it is the principle and foundation of the church. Hence it cannot be certainly and infallibly known except from the Scripture. The church is better known than the Scripture by us with a confused and inchoate knowledge because it is the means and instrument which leads us to the Scripture and which draws it to us. Thus the Scripture and the church give each other mutual help; but the authority belongs to the Scripture and the ministry to the church. The church shows the Scripture by her ministry and a posteriori, as the effect the cause and a light the candlestick; the Scripture shows the church by her authority and a priori, as the cause the effect. XXII. To no purpose does Perronius cavil when he objects that "doctrine can­not be a mark of the church, neither that which is not controverted because all agree concerning it, and thus it is not a mark of distinction, but rather of union; nor the controverted because it is undecided, nor can a decision be made except by the church." Answer: (1) we do not say simply that doctrine is a mark of the church, but inasmuch as it is conformed to the Scripture (the principle received among Christians). If there were no rule for deciding controversies or it was so obscure that it could hardly and not even hardly be known, I confess that a doc­trine controverted could not be a mark. But we have a canon in the word accord­ing to which the pious can be easily taught concerning the truth of its con­formity with the rule. (2) Doctrine not controverted (such as the Lord's sermon, the law and the Apostles' Creed) can decide a controverted doctrine if it agrees with or differs from it. Thus the affirmative articles concerning which we agree are the rule of the negative concerning which we dispute, as the right is the in­dex of itself and of the wrong. For if Christ is our Mediator and Advocate, on that very account he ought to be the only one because he is impatient of an asso­ciate. If the sacrifice of the cross of Christ is a propitiation (hilastikon), there can be no room for another; If Christ is the head of the church, therefore there can­not be a pope because they are incompatible (asystata) with each other. (3) If be­cause an adversary raises a controversy, a certain mark ceases to be a mark, all the marks brought forward by our opponents would be in danger because they can be controverted. XXIII. No better is his supposition that conclusions concerning faith and in­fallible decisions cannot be made except by an infallible means which can be neither human reasoning (which is fallible) nor private inspiration (which can often be fallacious) but only the authority of the church (which God has given to us as an infallible interpreter). (1) The infallibility of the object or of the doc­trines is falsely confounded with the infallibility of the subject or the human in­tellect. Doctrines have an absolute infallibility, but the human intellect has properly no infallibility (although it has its own certainty in working, which does not deceive). Nor is it necessary that what is fallible in its own nature, always ac­tually deceives; otherwise there would be no certainty of knowledge (which nevertheless there is). There is no need, therefore, that the means which lead us to the knowledge of an infallible doctrine should at once be infallible. It suffices that it be such as (rightly employed) does not deceive. Thus the human mind (not alone, but enlightened by the Holy Spirit) can be such a means by which the truth can be distinguished from error. In this sense, Paul says the spiritual man judges all things (1 Cor. 2:15) and John says that the anointing teaches us all things (1 Jn. 2:27). Thus there is no need for a believer to be subjected to any ec­clesiastical tribunal to know the doctrine, since there is no apostle (nay, not even an angel and much less any pope or council) who is not subject to that examination, according to the oracle of Paul (Gal. 1:8). Nor if fanatics falsely boast of their inspirations, does it follow that the believer cannot be certainly persuaded of his inspiration; as the wise man does not cease to know certainly that he is sound in mind and reasons well, although an insane man claims the same for himself. (2) The cardinal falsely confounds the internal means and organs of knowledge with the external object when he compares together rea­soning, inspiration and the authority of the church. For reasoning and inspira­tion are the internal means and organs by which we arrive at a knowledge of the truth; but the authority of the church is the external means which has the rela­tion of the object which proposes it. Now if the two former means are fallible, they will be equally so as much with respect to the church as to the Scripture; nor can they err less in receiving the decisions of councils than in judging the doctrines of Scripture. XXIV. It cannot be said that the simple crowd and rustics are not capable of examining doctrine and so need other sensible marks which are better suited to their comprehension. It is treated here not of any doctrine whatsoever and of all the questions which can be agitated about it, but only of the doctrine necessary to salvation, in which the essence of faith consists (which stands out perspicuously in the Scriptures and can be perceived by any believer). Otherwise, in vain would the psalmist say the law of God makes wise the simple (Ps. 19:7*) and Paul say that Timothy from a child had known the holy Scriptures, which are able to make him wise unto salvation (2 Tim. 3:15), and that "the spiritual man discemeth all things" (1 Cor. 2:15). Nor is it less difficult for the simple people to ascertain the marks of the church which are brought forward by the Romanists and to assent to their truth than to make an examination of doctrine (as will be proved hereafter). XXV. Although it is not necessary that a mark should be the essential form of the thing or its specific difference, still it does not hinder it from being a mark; nay, no more certain mark can be granted, since form gives being to a thing. Nor is it an obstacle that the forms and differences of things for the most part lie con­cealed. The mark, however, ought to be sensible and external. For natural and bodily things which strike the senses and whose marks consequently ought to be external and sensible differ from spiritual and moral, which fall under the in­tellect. Now such is the church (about which we inquire), which has its own moral and spiritual being, because it is not regarded here simply as an assembly of men united with each other by external acts of religion, but by true faith in Christ and a sincere administration of the sacraments. This truth of faith and purity of divine worship, however, is discerned only in the intellect through a comparison of the doctrine with the word. XXVI. When the church is shown by doctrine, no more is the same declared by the same than when the thing defined is explained by the definition. For although the definition agrees with the thing defined (nor differs really from it), still it is clearer and plainer than the thing which makes known: as when I say, man is an animal endowed with reason; a grammarian is one who knows or teaches grammar. Nor can it be called a begging of the question, because a thing is explained by its form and difference. XXVII. Although an infidel and heretic can come to a confused and obscure knowledge of the church sooner than to the knowledge of doctrine, still never could he be certainly and infallibly persuaded of the truth of the church and of its purity and impurity, unless the purity or impurity of doctrine on which the church is founded was first known. Material knowledge is of the sense and does not produce demonstration, but no formal knowledge can be given unless the form is known and it is proved that this form is in this material. XXVIII. A mark is either regarded in itself and in the abstract or in the con­crete inasmuch as it is applied to any subject; as the seal of a prince is either at­tended to in itself and with respect to its own nature and the use to which it is destined, or with respect to the application which is made to letters, or to the things which ought to be sealed. In the former sense, the mark of the church is in Scripture because this is the rule, canon and standard of all truth. In the latter, this mark is the impress of the church by profession of doctrine and a practice of divine worship conformed to the Scripture. When it is asked concerning the mark of the church (inasmuch as it can be distinguished from other societies), it is not understood in the former, but in the latter sense, by reason of its con­formity with the word. XXIX. From what has been said, it is evident that truth of doctrine or con­formity with the word of God is the true and genuine mark of the true church in thesi. Afterwards also it is not difficult to gather in hypothesi what is that true church to which we are bound to join ourselves in order to obtain salvation. Whether it is the modem Roman church, which retains so many capital errors and idolatries altogether (dis dia pason) opposed to the word of God in faith and worship; or, on the other hand, ours, which is content with the word of God alone. But concerning these more must be said hereafter.