“Right” (ius) is defined by St. Thomas in strictly objective terms as ipsa res iusta, a just thing, something that is due. Such “just thing” is always an honest good. Therefore, it is a contradiction in terms to talk of sinful actions as “rights.”
To explain better the notion of what is due, Catholic doctrine distinguishes between innate and acquired rights.
Innate rights are strictly natural, absolute, founded on nature of man. They flow from the necessary end of man, to which he is destined by his nature. This natural necessity gives him the right to procure, without hurting others, what is needed to attain his end. Such rights are inherent in human nature; they cannot be alienated or perish in what regards their substance, although an individual may abstain from their exercise when he is not obliged, and even formally renounce them to attain a greater perfection.
Acquired rights are founded on a free, contingent fact—that is, on something that could have happened or not, depending on the free action of somebody. For example, I may choose to buy a book or not, but once I have decided to buy a book and reached an agreement with the seller, the book is due to me at the same time that the payment is due to the seller. Such rights can be lost or transferred to another.
In consequence, we can say that the true natural rights of man are inherent to his very nature. In relation to God, man has no rights, but in relation to other men, he has right to enjoy the goods that are in conformity with his nature—that is, those goods are due to him.
They are also anterior to the State, who cannot violate them. Primordial and inalienable, these rights exist before any temporal authority; they are not granted by it. The State must acknowledge and protect them, and never sacrifice them to the general good.
And last but not least, they are founded upon God. As human nature is given by God, the rights of nature are thus founded upon God. True rights flow from man’s duties towards God—we have rights regarding our life, family, patrimony, cult, because on those things we have duties towards God.
Hence, considering that man is composed of spiritual soul (intellect, free will) and a material body (senses, movement), there are two principal, totally imprescriptible natural rights—the right to know the truth and the right to pursue the good necessary to attain happiness and our ultimate end (i.e., God and all that helps to attain Him). God does not take these rights away from man in this life; consequently, no man can take them away from another man.
There are two other natural rights which are not imprescriptible—i.e., they may be lost as a legitimate punishment for crime: the right to exercise our liberty in what is not contrary to our duties towards God and our neighbor, and the right to preserve our person and goods.
Unfortunately, the modern world proclaims and protects as “human rights” things that are not such. Some of them are false because their foundation is bad, as they are founded solely upon the will of man, not on nature (that is, on God, the creator of nature). Others are false because their objects are unjust, as they are against divine and natural law—for example, the so-called “right to abortion.” Finally, some are false because their extension is abusive, as when some acquired rights are claimed as natural (innate).
In itself (per se), in the face of evil and error, the only practical attitude permitted is war, repression, hatred. In normal circumstances, it is the only way to stop what is evil and procure the good.
But exceptionally (per accidens), there may exist cases in which the repression of an evil risks causing greater evils than the one that we are trying to stop, or cases in which, through the patient, temporary endurance of the evil, great goods are expected.
As St. Thomas Aquinas explains, “The government of men derives from the government of God and must imitate it. Now, God—almighty and infinitely good—permits the evil that happens in the universe: while He could banish it, He endures it, either to draw a great good, or to avoid greater evils. In like manner, [we] can lawfully tolerate certain evils, to avoid greater ones, or to obtain a great good” (II-II, 10, 1, ad corpus).
In exceptional circumstances, then, an exceptional change of attitude is understandable—instead of immediate repression, tolerance.
Tolerance is the negative permission of an evil.
Its object is an evil that, for a serious reason, here and now cannot be avoided. It constitutes a simple permission: it allows that evil to subsist. The permission is simply negative: it is given because one cannot do otherwise.
Tolerance is not simply passive endurance, but a positive act of will by which one abstains, in this concrete and limited case, from repressing what should be repressed. It does not imply an approval or the granting of freedom to act, because freedom regards only what is good. In fact, it strongly implies the disapproval of that which is tolerated. Tolerance is a good—but the evil tolerated remains evil.
We can choose, will and love tolerance, because—in the concrete circumstances—it is a good. But even in exceptional circumstances, we cannot choose, will and love the evil tolerated, because it is always an evil. If we are impeded to fight the evil, we nevertheless have to hate it and to avoid any compromise with it.