In previous essays I explained how the traditional Christian view of private property hinged on the deleterious effects of original sin on human nature. As R.W. and A.J. Carlyle wrote in their magisterial six-volume work, A History of Medieval Political Theory in the West (1950, I: 123) the views expressed by Augustine (364-430) and Pope Gregory the Great (540-604) typified the approach of the Catholic Church for many centuries:

[B]oth St. Augustine and St. Gregory look upon the institution of coercive government as not belonging to the primitive state of man; they do not think that government of this kind is a natural institution; but this does not mean that the Fathers look upon the ordered government of society among men as they actually are, as a thing improper or illegitimate. We have already, in considering their attitude to the institution of slavery, recognized that they conceive of the conditions proper to human life as having been completely altered by the entrance of sin into the world. Slavery was contrary to the natural law of the primitive condition of human innocence, but is proper and even useful under the actual conditions of human nature. It is the same with the institution of government. Coercive government has been made necessary through sin, and is a divinely appointed remedy for sin.

As we have seen in my last several essays, private property was the third part of this trinity. If not for original sin, only common property would have been consistent with natural law, but with the Fall came the corruption of human nature with evil tendencies (primarily avarice, or greed), so God mandated private property to deal with this new condition. Private property, by distinguishing mine from thine, established boundaries, specified and enforced by government, designed to keep avarice in check and to punish violators. This is essentially what Augustine meant in saying that private property was decreed by God as a remedy and punishment for sin. As A.J. Carlyle explained in “The Theory of Property in Medieval Theology” (an article in Property: Its Duties and Rights, 1913), the Christian position led to the conclusion that private property is conventional, that it exists only in virtue of governmental laws and decisions:

These theories are intelligible only when brought into relation with that fundamental conception of the contrast between the natural and the conventional….This view is the opposite of that of Locke, that private property is an institution of natural law, and arises out of labour. To the Fathers the only natural condition is that of common ownership and individual use. The world was made for the common benefit of mankind, that all should receive from it what they require. They admit, however, that human nature being what it is, greedy, avaricious, and vicious, it is impossible for men to live normally under the condition of common ownership. This represents the more perfect way of life, and this principle was represented in the organization of the monastic life, as it gradually took shape. For mankind in general, some organization of ownership became necessary, and this was provided by the State and its laws, which have decided the conditions and limitations of ownership. Private property is practically the creation of the State, and is defined, limited, and changed by the State.

The natural-law theory of private property, as defended by John Locke and many other classical liberals, took many centuries to emerge. Some changes began to appear in the later Middle Ages. The intense interest in Roman Law—the so-called “reception” that began to take off in the eleventh century—and the largely spontaneous development of Feudal Law played important roles, as did the rediscovery of Aristotle’s works, beginning in the mid-twelfth century. Some church authorities reacted negatively to any effort to Christianize Aristotle, given how his naturalistic viewpoint conflicted with Christian beliefs. Among the dangers were Aristotle’s teachings that the universe has existed eternally, his denial of the personal immortality of the soul, and his implicit rejection of miracles, which followed from the Aristotelian doctrine that natural causation is everywhere operative.

Nevertheless, these obstacles were eventually overcome, thanks primarily to Thomas Aquinas and his grand synthesis, the Summa Theologica, which adroitly combined Christianity and the general perspective of “the Philosopher.” This was a significant innovation for the time, but as the Christian version of Aristotle became a pillar of orthodoxy it retarded some aspects of scientific progress. (This negative influence should not be exaggerated. The primary problem with Aristotle was in the field of physics; in biology and botany his influence was largely beneficial.)

There was nothing resembling original sin in the writings of Aristotle, and his conception of the “natural” differed from the traditional Christian conception. The “natural,” for Aristotle, did not signify an original, or primitive, condition, as we find in the theory of a Golden Age defended by Stoics and Christians; rather the “natural” signified the goal-directed development of an entity or social state into a more perfect, fully developed condition, as when an acorn grows into an oak tree. As Walter Ullmann noted in Medieval Political Thought (1975), this was a dramatic shift from the traditional Christian view:

Aristotle’s thought was pervaded by the idea of nature as the driving force, which was conceived in teleological terms: “Nature does nothing superfluous,” or “Nature behaves as if it foresaw the future,” or “Nature does nothing in vain,” were some of his often recurring statements which, with their strong teleological bias, could hardly fail to fall on receptive ears—and yet, what a difference there was between his and the traditional theology: the laws of nature determined man’s thinking and reasoning capacity. [T]he hallmark of man was the employment of his will and reason by which the laws of nature were expressed.

The upshot of Aristotle’s social doctrines was that the state, private property, and slavery were natural institutions that developed over time to serve the rational purposes of human beings. In adopting similar positions about those institutions, Aquinas typically cited Aristotle (especially the Politics) as his source. Consider Aquinas’s defense of slavery in his Summa Theologica: “Slavery among men is natural, for some men are naturally slaves, as the Philosopher proves at Politics I.” And again:

The fact that this man is a slave rather than that is due not to the nature of the man considered simply as such, but to some advantage consequent upon his being so, in that it is beneficial for a slave to be governed by someone wiser than he, and for a master to be assisted by the slave, as the Philosopher says at Politics I.

Likewise, when reviewing the nature and justification of the state (conceived in this context as an organized political community governed by laws, not merely as a ruling body, or “government” in the narrow sense), Aquinas again embraced the perspective of Aristotle, in part if not in total. The state is not a deviation from the original natural law, as earlier theologians had claimed. Although Aquinas agreed with the traditional view that a coercive government would have been unnecessary in man’s innocent, prelapsarian condition, he nevertheless maintained that the state is “natural” in the sense that it is based on human nature, is justified by human reason, and is essential for men to achieve their full potential as human beings.

Lastly, as we would expect, private property was justified by Aquinas along the same lines, with Aristotle again cited as his chief authority. Consider Aquinas’s reply to the argument that Christians should reject private property as contrary to natural law because common property was the original condition of mankind before Adam’s Fall into sin:

Community of goods is attributed to the natural law not because natural right dictates that all things should be possessed in common and that nothing should be possessed as one’s own, but because the division of possessions is not according to natural right, but, rather, according to human agreement, which belongs to positive right….Hence the ownership of possessions is not contrary to natural right; rather, it is an addition to natural right devised by human reason.

Although we are still a long way from Locke’s argument that private property is a natural right originally based on labor, Aquinas moved closer to the modern liberal view that private property advances a positive social good and is not merely a remedial and punitive institution mandated by God for sinful human beings. The essential role played by private property in maintaining peaceful social cooperation is a discovery of human reason, so private property is “natural” in that sense. Reason has supplemented the original natural law, not contradicted it.

Before concluding this essay, I wish to make an important observation about the status of private property in emergency situations, as when a man would starve if he did not steal food from another person. From the early Church Fathers through the Middle Ages and well into the modern era, it was argued that a man in dire need has a right to the property of those people who possess more property than they reasonably need. It must be understood that this was seen as a positive, enforceable right, not merely as a moral mandate for voluntary charity. Strictly speaking, if a starving man absconds with food that belongs to a wealthy man, he is not “stealing” at all; he is simply taking that which belongs to him by right.

Although this right found in emergency scenarios was justified in various ways, it was closely linked to the premise that God originally gave the earth and its resources to mankind in common for the benefit of all. Christian theologians, early and late, unanimously argued that a surplus of private property (i.e., more property than is needed to satisfy one’s basic needs) is justifiable only if such property is used for the common good. As Aquinas put it, “man ought to hold external things not as his own, but as common: that is, in such a way that he is ready to share them with others in the event of need.” Human need trumps private property rights in emergency situations; so, as Aquinas explained, for a starving man to take food from a rich man, even without the permission of the latter, does not qualify as an unjust act at all.

If…there is a necessity so urgent and clear that it is obvious that the necessity must be met at once by whatever means are to hand—for example, if a person is in immediate danger and no other help is available—anyone can then lawfully supply his own need from the property of another by taking from it either openly or in secret; nor, properly speaking, does this have the character of theft or robbery. 

This doctrine survived even in the writings of leading Protestant natural-law philosophers during the seventeenth century, whose overall approach tended to be more secular than that of their Catholic counterparts. For example, when Hugo Grotius defended this emergency right, he added that when necessity compels me to take the property of another person, “I certainly ought to make that Man Restitution as soon as I am able to do it.” This position on restitution was later criticized by Samuel Pufendorf, who correctly pointed out that one cannot legitimately demand restitution from a person in need if that person is merely exercising his natural right to appropriate and use the property of others. Where no injustice had been committed, no restitution is required.

Oddly perhaps, the same emergency right was defended by John Locke in his First Treatise of Government: “Charity gives every man a Title to so much out of another’s Plenty, as well keep him from extreme want, where he has no means to subsist otherwise.” In using the word “Title,” Locke made it clear that he was speaking not merely of a moral obligation to be charitable but of a positive right enforceable by government. Although early defenders of this right almost always applied it narrowly to life-or-death situations, later defenders of the welfare state easily adapted the same premise to justify their schemes for the extensive redistribution of private property by governments.