All things are clean to the clean: but to them that are defiled, and to unbelievers, nothing is clean: but both their mind and their conscience are defiled.

all things, indeed, are pure to the pure, and to the defiled and unstedfast is nothing pure, but of them defiled are even the mind and the conscience;

To the pure everything is pure; but to the polluted and unbelieving nothing is pure, but on the contrary their very minds and consciences are polluted.

To the clean in heart all things are clean: but to those who are unclean and without faith nothing is clean; they become unclean in mind and in thought.

All things are clean to those who are clean. But to those who are defiled, and to unbelievers, nothing is clean; for both their mind and their conscience have been polluted.

To those whose minds are pure, all things are ritually pure, but to those whose minds are tainted and unbelieving nothing is pure, as their minds and consciences are alike polluted.

omnia munda mundis coinquinatis autem et infidelibus nihil mundum sed inquinatae sunt eorum et mens et conscientia

To the pure all things indeed are pure He glances at one class of fabulous opinions; for the choice of the kinds of food, (such as was temporarily enjoined by Moses,) together with purifications and washings, were insisted on as being still necessary, and they even made holiness to consist almost wholly in these minute observances. How dangerous to the Church this was, we have already explained. First, a snare of bondage was laid on the consciences; and next, ignorant persons, bound by this superstition, had a veil drawn over their eyes, which hindered them from advancing in the pure knowledge of Christ. If any of the Gentiles refused to submit to this yoke, because he had not been accustomed to it, the Jews vehemently contended for it, as if it had been the chief article of religions. Not without good reason, therefore, does Paul firmly oppose such corrupters of the gospel. In this passage, indeed, he not only refutes their error, but wittily laughs at their folly, in laboring anxiously, any advantage, about abstaining from certain kinds of food and things of that nature In the first clause of this verse he upholds Christian liberty, by asserting, that to believers nothing is unclean; but at the same time he indirectly censures the false apostles who set no value on inward purity, which alone is esteemed by God. He therefore rebukes their ignorance, in not understanding that Christians are pure without the ceremonies enjoined by the Law; and next he chastises their hypocrisy, in disregarding uprightness of heart, and occupying themselves with useless exercises. But as the subject now in hand is not the health of the body, but peace of conscience, he means nothing else than that the distinction of the kinds of food, which was in force under the Law, has now been abolished. For the same reason it is evident, that they do wrong, who impose religious scruples on consciences in this matter; for this is not a doctrine intended for a single age, but an eternal oracle of the Holy Spirit, which cannot lawfully be set aside by any new law. Accordingly, this must be true till the end of the world, that there is no kind of food which is unlawful in the sight of God; and, therefore, this passage is fitly and appropriately quoted in opposition to the tyrannical law of the Pope, which forbids the eating of flesh on certain days. And yet I am not unacquainted with the sophistical arguments which they employ. They affirm, that they do not forbid the eating of flesh, because they allege that it is unclean, (for they acknowledge that all kinds of food are in themselves clean and pure,) but that abstinence from flesh is enjoined on another ground, that it has a tendency to tame the lust of the flesh; as if the Lord had forbidden to eat swine's flesh, because he judged swine to be unclean. Even under the Law the fathers reckoned that everything which God created is in itself pure and clean; but they held that they were unclean for this reason, that the use of them was unlawful, because God had forbidden it. All things are, therefore, pronounced by the Apostle to be pure, with no other meaning than that the use of all things is free, as regards the conscience. Thus, if any law binds the consciences to any necessity of abstaining from certain kinds of food, it wickedly takes away from believers that liberty which God had given them. But to the polluted and unbelieving nothing is pure. This is the second clause, in which he ridicules the vain and useless precautions of such instructors. He says that they gain nothing by guarding against uncleanness in certain kinds of food, because they cannot touch anything that is clean to them. Why so? Because they are "polluted," and, therefore, by their only touching those things which were otherwise pure, they become "polluted." To the "polluted" he adds the "unbelieving," [1] not as being a different class of persons; but the addition is made for the sake of explanation. Because there is no purity in the sight of God but that of faith, it follows that all unbelievers are unclean. By no laws or rules, therefore, will they obtain that cleanness which they desire to have; because, being themselves "polluted," they will find nothing in the world that is clean to them. [2] But their mind and conscience are polluted. He shows the fountain from which flows all the filth which is spread over the whole life of man; for, unless the heart be well purified, although men consider works to have great splendor, and a sweet smell, yet with God they will excite disgust by their abominable smell and by their filthiness. "The Lord looketh on the heart," (1 Samuel 16:7,) and "his eyes are on the truth." (Jeremiah 5:3.) Whence it arises, that those things which are lofty before men are abomination before God. The mind denotes the understanding, and the conscience relates rather to the affections of the heart. But here two things ought to be observed; first, that man is esteemed by God, not on account of outward works, but on account of the sincere desire of the heart; and, secondly, that the filth of infidelity is so great, that it pollutes not only the man, but everything that he touches. On this subject let the reader consult Haggai 2:11-14. In like manner Paul teaches that "all things are sanctified by the word," (1-Timothy 4:5,) because men use nothing in a pure manner till they receive it by faith from the hand of God.

Footnotes

1 - "The Apostle joins defiled' and unbelieving,' to intimate that, without a true belief, nothing is clean. The understanding and the conscience are polluted. Both the man and his doings are impure." -- Hervey.

2 - "It is a dreadful condemnation pronounced on men, when it is said that nothing is clean to them -- that all is polluted and defiled, till God has renewed them. So far are we from being able to bring anything that is acceptable to him, that we can neither eat nor drink, nor put on our clothes, nor walk a single step, without corruption, and, what is more, by dwelling in the world we infect all the creatures. And this is the reason why they must call for vengeance at the last day against all unbelievers and reprobates. We have, therefore, good reason to be dissatisfied with ourselves and to be ashamed, when we see that they become hateful on our account and that we are so polluted as to have infected every thing that God had appropriated to our use, and even that there is nothing in us but all corruption -- nothing but a God cursed and disowned. When we are thus humbled, let us know, on the other hand, the inestimable blessing which God bestows on us, when he brings us back to himself, and, after having cleansed us, causes us to use all his blessings and bounties: with purity of heart and when we are assured that it is lawful for us to eat and drink, provided that we do so with all sobriety, and in a reasonable manner." -- Fr. Ser.

Unto the pure all things are pure - See the notes at Romans 14:14, Romans 14:20. There is probably an allusion here to the distinctions made in respect to meats and drinks among the Jews. Some articles of food were regarded as "clean," or allowed to be eaten, and some as "unclean," or forbidden. Paul says that those distinctions ceased under the Christian dispensation, and that to those who had a conscience not easily troubled by nice and delicate questions about ceremonial observances, all kinds of food might be regarded as lawful and proper; compare the notes at 1-Timothy 4:4-5. If a man habitually maintains a good conscience in the sight of God, it will be accepted of him whether he do or do not abstain from certain kinds of food; compare the notes at Colossians 2:16. This passage, therefore, should not be interpreted as proving that all things are right and lawful for a Christian, or that whatever he may choose to do will be regarded as pure, but as primarily referring to distinctions in food, and meaning that there was no sanctity in eating one kind of food, and no sin in another, but that the mind was equally pure whatever was eaten.
The phrase has a proverbial cast, though I know not that it was so fused. The principle of the declaration is, that a pure mind - a truly pious mind - will not regard the distinctions of food and drink; of festivals, rites, ceremonies, and days, as necessary to be observed in order to promote its purity. The conscience is not to be burdened and enslaved by these things, but is to be controlled only by the moral laws which God has ordained. But there may be a somewhat higher application of the words - that every ordinance of religion, every command of God, every event that occurs in divine Providence, tends to promote the holiness of one who is of pure heart. He can see a sanctifying tendency in everything, and can derive from all that is commanded, and all that occurs, the means of making the heart more holy. While a depraved mind will turn every such thing to a pernicious use, and make it the means of augmenting its malignity and corruption, to the pure mind it will be the means of increasing its confidence in God, and of making itself more holy. To such a mind everything may become a means of grace.
But unto them that are defiled and unbelieving is nothing pure - Everything is made the means of increasing their depravity. No matter what ordinances of religion they observe; what distinctions of meats, or drinks, or days they regard, and what events of Providence occur, all are the occasion of augmented depravity. Such distinctions in food they make the means of fostering their pride and producing self-righteousness; the mercies of God they abuse to pamper their own lusts, and the afflictive events of Divine Providence they make the occasion of murmuring and rebellion. Naturally corrupt at heart, no ordinances of religion, and no events of Providence, make them any better, but all tend to deepen their depravity. A sentiment similar to this is found in the classic writers. Thus Seneca, Epis. 98. Malus animus omnia in malum vertit, etiam quae specie optimi venerunt. So again (de Beneficiis v. 12), (Quemadmodum stomachus morbo vitiatus, et colliques bilem, quoscunque acceperit cibos mutat - ita animus caecus, quicquid fill commiseris, id onus suum et perniciem facited.
But even their mind and conscience is defiled - It is not a mere external defilement - a thing which they so much dread - but a much worse kind of pollution, that which extends to the soul and the conscience. Everything which they do tends to corrupt the inner man more and more, and to make them really more polluted and abominable in the sight of God. The wicked, while they remain impenitent, are constantly becoming worse and worse. They make everything the means of increasing their depravity, and even these things which seem to pertain only to outward observances are made the occasion of the deeper corruption of the heart.

Unto the pure all things are pure - This appears to have been spoken in reference to the Jewish distinctions of clean and unclean meats. To the genuine Christian every kind of meat proper for human nourishment is pure, is lawful, and may be used without scruple. This our Lord had long before decided. See on Luke 11:39-41 (note).
But unto them that are defiled - In their consciences, and unbelieving, απιστοις, unfaithful both to offered and received grace, nothing is pure - they have no part in Christ, and the wrath of God abides upon them. Their mind is contaminated with impure and unholy images and ideas, and their conscience is defiled with the guilt of sins already committed against God.

(11) Unto the pure all things [are] pure: but unto them that are defiled and unbelieving [is] nothing pure; but even their (o) mind and conscience is defiled.
(11) He shows in few words, that purity consists not in any external worship, and that which is according to the old Law (as indifference of meats, and washings, and other such things which are abolished) but in the mind and conscience. And whoever teaches otherwise, does not know what true religion really is, and also is not to be heeded.
(o) If our minds and consciences are unclean, what cleanness is there in us before regeneration?

Unto the pure all things are pure,.... The apostle having made mention of Jewish fables, and the traditions of the elders, takes notice of some darling notions, that these judaizing Christians had imbibed or retained; that there were some things, which being touched, or handled, or tasted, occasioned uncleanness, and which the apostle denies to them that are "pure"; by whom are meant, not such who are so in their own eyes, who yet may not be cleansed from their filthiness; nor do any become pure through ceremonial, moral, or evangelical performances, done by them; they are only pure, who are justified from all sin by Christ's righteousness, and are clean through the word or sentence of absolution spoken by him; and who are washed from their sins in his blood, and have that sprinkled upon their consciences, by which they are purged and cleansed from all sin; and who have the clean water of sanctifying grace sprinkled upon them, and have clean hearts, and right spirits created in them; and whose hearts are purified by faith, and have true principles of grace and holiness formed in them; whose graces are pure and genuine, their faith is unfeigned, their love is without dissimulation, and their hope without hypocrisy; and who, in consequence of all this, love pureness of heart, speak the pure language of Canaan, hold the mystery of the faith in a pure conscience, and follow after purity of life and conversation: to these "all things are pure"; whatever they touch, or handle, or eat, nothing can defile them; for it is not what enters into man that can pollute him; nor is any creature unclean of itself, but good, and to be received with thanksgiving; see Matthew 15:11.
But unto them that are defiled and unbelieving is nothing pure; all mankind are defiled with sin; they are altogether become filthy; there is none good, no, not one; and all of them, or that belong to them, are unclean; the members of their body, and the powers and faculties of their soul, their mind and conscience, understanding, will, and affections; there is no place clean: they are originally so, from their first conception and birth; and they are actually defiled by their own evil thoughts, words, and doings: some are openly impure, like the dog and the swine, who wallow in their impieties, such are the profane part of the world; others are more secretly so, as those of a pharisaical complexion, nominal Christians, and formal professors; and such the apostle has here in view: and who, notwithstanding their profession of the Christian religion, were "unbelieving"; they had not true faith in Christ, though they professed it; they were not indeed unbelieving, as the Jews, who rejected Jesus as the Messiah: yet they did not purely and cordially embrace the doctrines of the Gospel, nor yield a spiritual and cheerful subjection to the ordinances of it; but were for mixing the ceremonies of the law with the institutions of Christ: and to these were "nothing pure"; right and lawful to be done, or not done, even in the case supposed, about eating things forbidden by the ceremonial law; to eat them would be to eat with offence, to their own consciences, on their principles, and so be evil, Romans 14:20 and to abstain from them on account of laws not in force, would be superstition and will worship, and so criminal, Colossians 2:21. There is nothing that defiled persons can do, but what is unclean; as are their persons, so are their offerings and works, Haggai 2:14, and being destitute of true faith, whatever they do is sin, and not anything they do can be acceptable and well pleasing to God, Romans 14:23. There were some things among the Jews, which were prohibited to them that were defiled, and were free to them that were pure: thus, for instance (u),
"the flesh of the most holy things, and the flesh of those which are lightly holy, boiled with flesh of delight, (or common flesh,) are forbidden "to the defiled", but are free "to the pure".''
Which one of their commentators (w) thus explains;
"the flesh of the most holy things is forbidden to strangers, though pure; the flesh of things lightly holy is free to strangers that are pure, but forbidden to them that are defiled.''
Whether there may be any allusion to this, may be considered: however, the reason the apostle gives why nothing is pure to the impure, is, because of the pollution of the superior powers and faculties of their soul:
but even their mind and conscience is defiled; there is nothing in them, or that belongs to them, that is pure; their mind or understanding, which conceives and judges of things, and forms notions of them; and the conscience, which draws conclusions from them, are both defiled with sin; and what then must the thoughts, the words and actions of such persons be? it matters not what they do, or abstain from, what they touch, taste, or handle, or if they do not, they sin in all they do.
(u) Minn. Orla, c. 2. sect. 17. (w) Bartenora, in Misn. Orla, c. 2. sect. 17.

all things--external, "are pure" in themselves; the distinction of pure and impure is not in the things, but in the disposition of him who uses them; in opposition to "the commandments of men" (Titus 1:14), which forbade certain things as if impure intrinsically. "To the pure" inwardly, that is, those purified in heart by faith (Acts 15:9; Romans 14:20; 1-Timothy 4:3), all outward things are pure; all are open to, their use. Sin alone touches and defiles the soul (Matthew 23:26; Luke 11:41).
nothing pure--either within or without (Romans 14:23).
mind--their mental sense and intelligence.
conscience--their moral consciousness of the conformity or discrepancy between their motives and acts on the one hand, and God's law on the other. A conscience and a mind defiled are represented as the source of the errors opposed in the Pastoral Epistles (1-Timothy 1:19; 1-Timothy 3:9; 1-Timothy 6:5).

To the pure - Those whose hearts are purified by faith this we allow. All things are pure - All kinds of meat; the Mosaic distinction between clean and unclean meats being now taken away. But to the defiled and unbelieving nothing is pure - The apostle joins defiled and unbelieving, to intimate that nothing can be clean without a true faith: for both the understanding and conscience, those leading powers of the soul, are polluted; consequently, so is the man and all he does.