Sunday, September 29, 2019

How can you believe in the existence of natural rights?



In preceding articles on this blog I have traced the evolution of the concept of natural rights from ancient reasoning about natural law to the U.S. Declaration of Independence in 1776. The importance of the Declaration’s assertion of natural rights stems from the moral support its inspiring message has provided, and still provides, to people whose rights have been infringed or insufficiently recognised in the U.S. and elsewhere in the world.

Not long after the U.S. declared independence, some influential philosophers began to cast doubt on the concept of natural rights. The famous British statesman and political philosopher, Edmund Burke, argued that “the primitive rights of man undergo such a variety of refractions and reflections, that it becomes absurd to talk of them as if they continued in the simplicity of their original direction” (Reflections on the Revolution in France, 1790).

Jeremy Bentham, the founder of utilitarianism, argued that only political rights – rights established and enforced by governments have “any determinate and intelligible meaning”. He viewed natural rights as “rhetorical nonsense, nonsense upon stilts” (Anarchical Fallacies, 1796).

Much modern questioning of the existence of natural rights stems from doubts about the existence of a Creator who could endow them in the manner suggested by the authors of the U.S. Declaration of Independence. Michael Birshan has suggested that although it is plausible that there is a system of natural rights instituted by a Supreme Being, “it is much less plausible that man could ever discover them through rational reasoning”.

Does it make sense to view natural rights as stemming from our human nature, without necessarily involving the intervention of a Supreme Being? I believe it does. I advance two overlapping lines of argument below to support the view that natural rights are inherent in the nature of humans.

The first line of argument stems from Aristotle’s observations about the natural potential for individual humans to flourish. As explained recently on this blog, an understanding of the nature of human flourishing implies that individuals have liberty to exercise responsibility for self-direction. In one of the first posts published on this blog I drew attention to the observation of Douglas Rasmussen and Douglas Den Uyl about the role of liberty in protecting “the possibility of agency or self-direction, which is central to any and every form of human flourishing”.

However, that line of argument doesn’t fully explain why you and I have strong moral intuitions that we, and Mr Xi, should recognise that other individual humans have the right to exercise the self-direction that is central to their flourishing.

My second line of argument is that a capacity for moral intuitions is inherent in human nature and has evolved over time into the ethics of respect – the foundation of natural rights - as a consequence of natural processes of cooperation for mutual benefit.

In ancient times, the existence of such intuitions was recognised by Cicero, who argued that “respect for virtue” is a ubiquitous aspect of human nature and that “nature made us just that we might participate our goods with each other, and supply each other’s wants”.

In the 18th century, Francis Hutcheson also recognised such intuitions in discussing the “the right to natural liberty”:  “Every man has a sense of this right, and a sense of the evil of cruelty in interrupting this joyful liberty of others, without necessity for some more general good”.

More recently, intuitions about ethical treatment of others have been studied by Jonathan Haidt, a social psychologist, in The Righteous Mind: Why good people are divided by politics and religion, 2012.  The basic idea of his moral foundations theory is that our moral intuitions are related to adaptive challenges of social life that have been identified by evolutionary psychologists. Moral foundations are innate, but they are expressed in differing ways and to differing extents in different cultures. I have high regard for Haidt’s moral foundations theory but, as noted previously, in my view his survey methods exaggerate the extent that people who give high priority to liberty are undisturbed by feelings of empathy and disgust.

The best philosophical discussion I am aware of about the evolution of the ethics of respect is that by Robert Nozick in Invariances, 2001. Nozick began his earlier, and more famous, book, Anarchy, State and Utopia, by assuming a state of nature in which individuals are in a “state of perfect freedom”. He noted that he was “following the respectable tradition of Locke, who does not provide anything remotely resembling a satisfactory explanation of the status and basis of the law of nature in his Second Treatise”. Chapter 5 of Invariances does seem to me to provide a satisfactory explanation of how moral intuitions might have evolved naturally to support the ethics of respect.

Nozick’s argument can be briefly summarised as follows:
  • The higher capacities of humans, including capacities for conscious thought, control of impulses and planning, have been selected for by evolution because of the benefits they bring e.g. in enabling adherence to ethical norms.
  • The use of norms to guide behaviour enables humans to extend the realm of cooperative behaviour for mutual benefit beyond what would otherwise be possible.
  • Cooperative behaviour for mutual benefit includes, among other things adherence to norms of non-interference – refraining from murdering, enslaving and stealing from others – provided they are willing to reciprocate. 
  • The impetus to extend the sphere of voluntary cooperation for mutual advantage beyond the immediate family or group is the perception that this brings benefits greater than can be obtained otherwise e.g. by involuntary exchanges. That has been an important component of the history of ethical progress, even though there has been much backsliding
  • Evolution may have shaped humans to enjoy cooperative activity. A reputation for adhering to norms of cooperative behaviour brings rewards by attracting further cooperation, and may have conferred reproductive advantages.
  • The internalisation of norms enables them to be followed even when no-one is watching who can sanction deviations. Internalisation brings ethics into play. Something other than (or in addition to) punishment by other people must support rules if they are to become ethical principles or values.
  • The evaluative capacities of humans enable them to generalise from different experiences of cooperative behaviour for mutual benefit and to identify common properties in a range of experiences. In turn, those abilities make persons less prone to the push and pull of desires and more prone to feel uncomfortable when their evaluations are discordant. (An example of the latter is conflict between a desire to enforce traditional norms relating to religious observance and to advance norms of non-interference.)
  • Moral progress involves, among other things, shrinkage of the domain of mandatory morality to enable a domain of liberty and personal autonomy to be established, and for the ethics of respect to emerge. 

Nozick sums up:
 “if conscious self-awareness was selected for because it makes us capable of ethical behaviour, then ethics, even the very first layer of the ethics of respect, truly is what makes us human. A satisfying conclusion. And one with some normative force” (p 300).

Since the ethics of respect entails recognition of Lockean rights, Nozick’s naturalistic explanation implicitly recognises that such rights are natural.

Conclusion
It makes sense to believe that natural rights are inherent in the nature of humans. Individual humans have a natural right to exercise the self-direction that is central to their flourishing. Natural rights have normative significance as an outcome of a long evolutionary process involving development of moral intuitions, social norms and evaluative capabilities. That process explains why you and I have moral intuitions that we, and Mr Xi, should abide by the norms of liberty that maximize the opportunities available for all to flourish.

Wednesday, September 18, 2019

Why did the US Declaration of Independence specify an unalienable right to the pursuit of happiness?


Given that the United States was founded by politicians, is there is any point trying to understand why any particular words were included in the Declaration of Independence? I think there is.
The politicians who drafted the Declaration in 1776 seem to have been more thoughtful and principled in their approach than many contemporary politicians engaged in similar constitutional issues e.g. Brexit. More importantly, even if we  think the founders were engaged in a self-interested bid for power, in preparing their Declaration they were seeking the support of American colonists, so it was in their interests to express sentiments that would attract widespread support within those communities.

Thomas Jefferson, who wrote the first draft of the Declaration, maintained later that “it was intended to be an expression of the American mind”:
“All its authority rests then on the harmonizing sentiments of the day, whether expressed in conversation, in letters, printed essays, or in the elementary books of public right, as Aristotle, Cicero, Locke, Sidney, &c.”

A copy of an extract from Jefferson's draft:



The words relating to an unalienable right to pursuit of happiness were unchanged in the various drafts of the Declaration. Rather than pondering whether those words were borrowed from one source or another, it may be more illuminating to focus on why the ideas expressed by those words would have appealed to the intended audience of American colonists and their sympathisers.

The idea of individuals being “endowed by their creator” with “unalienable rights” would have appealed to numerous followers of John Locke among American colonists. Unalienable (or inalienable) rights continue to exist even when not recognized by governments; such natural rights cannot be taken away, sold, or given away. Locke’s view that the existence of a natural right to liberty provided justification for the overthrow a tyrannical government added philosophical support to the desire of colonists free themselves from British rule.

Was “pursuit of happiness” included merely as a rhetorical device? You and I might argue that a right to liberty implies a right for individuals to pursue happiness in whatever way they choose. However, some historians have suggested that in 18th century America there could have been a tendency for liberty to be interpreted in terms of the classical republican tradition of political participation, rather than in Lockean terms of freedom from violation of natural rights (see Darrin McMahon, Happiness, a history, p 324). In that context it seems to me that recognition of a natural right to pursue happiness might have been seen to offer additional protection e.g. in discouraging governments from attempting to control religious beliefs.

Darrin McMahon’s discussion of the meaning of “pursuit of happiness” in 18th century America aids understanding of why it would have been widely viewed as a natural right at that time. He notes that John Locke wrote of natural rights to “life, liberty and estate” rather than life, liberty and happiness. Nevertheless, Locke saw pursuit of happiness as an important feature of a divinely orchestrated natural world in which individuals seek pleasant sensations and have differing tastes. Locke’s view of happiness combined hedonism with goodness, the exercise of practical wisdom, and spirituality. He suggested that the “constant pursuit of true and solid happiness” … “which is our greatest good” … frees us “from any necessary determination of our will to any particular actions”. Locke saw heaven as offering the greatest of all pleasures.

McMahon also notes the important influence of Scottish Enlightenment philosophers, particularly Francis Hutcheson, in 18th century America. As noted in the preceding article on this blog, Hutcheson argued that humans possess a moral sense. We can obtain happiness by doing good!

Carli Conklin has suggested the English jurist, William Blackstone (1723 - 1780) as the source of another influential view about pursuit of happiness in 18th century America (‘The Origins of the Pursuit of Happiness’, Washington University Jurisprudence Review, 7/2, 2015). The founders strongly disagreed with Blackstone’s belief that the British parliament remained a supreme authority over the colonies. However, they agreed with him about natural law and the pursuit of happiness, and may have seen advantage in drawing on those views to highlight an inconsistency in his position.

In his Introduction to Commentaries on the Laws of England, Blackstone argues that individual pursuit of happiness is the foundation of natural law:
 “For [the Creator] has so intimately connected, so inseparably interwoven the laws of eternal justice with the happiness of each individual, that the latter cannot be attained but by observing the former; and, if the former be punctually obeyed, it can not but induce the latter. In consequence of which mutual connection of justice and human felicity, He has not perplexed the law of nature with a multitude of abstracted rules and precepts, referring merely to the fitness or unfitness of things, as some have vainly surmised; but has graciously reduced the rule of obedience to this one paternal precept, “that man should pursue his own happiness.” This is the foundation of what we call ethics, or natural law.”

The views of Benjamin Franklin about pursuit of happiness seem to draw together many threads of thinking on this topic in 18th century America. Carli Conklin quotes his views as follows:
‘Benjamin Franklin stated “[t]he desire of happiness in general is so natural to us that all the world are in pursuit of it” and although men may attempt to achieve happiness in different ways, the reality is that “[i]t is impossible ever to enjoy ourselves rightly if our conduct be not such as to preserve the harmony and order of our faculties and the original frame and constitution of our minds; all true happiness, as all that is truly beautiful, can only result from order.” Therefore, according to Franklin, if we pursue happiness through passion instead of reason, we achieve only an “inferior” and “imperfect” happiness, because “[t]here is no happiness then but in a virtuous and self-approving conduct.” Indeed, Franklin argued “the Science of Virtue is of more worth, and of more consequence to [man’s] Happiness than all the rest [of the sciences] put together.” Furthermore, Franklin stated, “I believe [God] is pleased and delights in the Happiness of those he has created; and since without Virtue Man can have no Happiness in this World, I firmly believe he delights to see me Virtuous, because he is pleas’d when he sees me Happy”.’

Conclusions
The US Declaration of Independence specified pursuit of happiness as an inalienable right because the founders knew that sentiment would attract widespread support among American colonists and their sympathisers. “Pursuit of happiness” was more than an attractive rhetorical device in a context where an inalienable right to liberty might have been interpreted in civic republican, rather than Lockean terms. 
Given the meaning of the pursuit of happiness in 18th century America - influenced by Locke, Hutcheson, Blackstone and Franklin, among others – it is easy to understand why it would have been widely recognised as a natural right. 
Pursuit of happiness was widely perceived in terms that have a great deal in common with the activity of human flourishing, as perceived by Aristotle and his followers. 

Wednesday, September 11, 2019

Where did Adam Smith's 'system of natural liberty' come from?


In Wealth of Nations, Adam Smith (1723 -1790) famously wrote that when all systems of government
preferment or restraint for particular “species of industry” are removed, “the obvious and simple system of natural liberty establishes itself of its own accord”.

He went on to explain what this system of natural liberty entails:
‘Every man, as long as he does not violate the laws of justice, is left perfectly free to pursue his own interest in his own way, and to bring forth both his industry and capital into competition with those of any other man, or order of men. The sovereign is completely discharged from a duty [for which] no human wisdom or knowledge could ever be sufficient; the duty of superintending the industry of private people, and of directing it towards the employments most suitable to the interest of the society’. (WN, IV.ix.51).

Smith’s use of the value-laden term, ‘natural liberty’, seems to have been intended to convey that it is good for everyone to be free to pursue their individual interests, even in the absence of more tangible mutual benefits. That ethical connotation is even stronger in other passages in Wealth of Nations (WN) where Smith refers to violations of natural liberty as unjust.

Jerry Muller suggests that “the display” of the ‘system of natural liberty’ contributes to the great persuasive power of the WN, but might “lead many readers to overlook the complexity of Smith’s conception of the moral life and to conclude that liberty, in itself, was always a good thing” (The Mind and the Market, 2002, p 83).

In my view, it is likely that Smith would have been pleased to have readers accept his vision of natural liberty and limited government as unambiguously good. I think he would have wanted people to recognise that it was an unjust infringement of natural liberty for the powers of government to be used to assist some economic groups at the expense of others.

Nevertheless, as Nicholas Phillipson highlights in his biography, Smith’s political prescriptions for market liberalisation were pragmatic. He recognised the need for a gradual approach to the removal of obstructions to avoid provoking dangerous opposition from opposing interests (Adam Smith, An enlightened life, 2010, p 230-31).

The authors of the introduction to the 1976 edition of The Theory of Moral Sentiments suggest that Smith’s reference to “the obvious and simple system of natural liberty” in WN reflects the influence on him of the Stoic concept of natural harmony. (The editors D. D. Raphael and A. L. Macfie acknowledge help from Walter Eckstein in writing the introduction.)

Smith’s reference to natural liberty could also reflect the influence of more recent philosophers, including Francis Hutcheson (1694 – 1746), who taught Smith moral philosophy at Glasgow university. Hutcheson’s philosophical interests included the nature of virtue, the meaning of sociability and natural rights. His teaching and writings were deeply respected in radical Whig circles in Britain and the American colonies.

Smith’s ideal of everyone being free to pursue their own interests in their own way seems to echo Hutcheson’s explanation of the right to natural liberty in terms of pursuit of happiness:
“As nature has implanted in each man a desire of his own happiness, and many tender affections toward others in some nearer relations of life, and granted to each one some understanding and active powers, with a natural impulse to exercise them for the purposes of these natural affections; 'tis plain each one has a natural right to exert his powers, according to his own judgment and inclination, for these purposes, in all such industry, labour, or amusements, as are not hurtful to others in their persons or goods, while no more public interest necessarily requires his labours, or requires that his actions should be under the direction of others. This right we call natural liberty.”

Smith and his followers would want to redraft that a little to define the meaning of what is hurtful to others in terms of fair play, or respect for their rights. There is also the question of how to define the “public interest” that apparently has priority over private interests.

 Hutchison goes on to assert:
“Every man has a sense of this right, and a sense of the evil of cruelty in interrupting this joyful liberty of others, without necessity for some more general good. Those who judge well about their own innocent interests will use their liberty virtuously and honourably; such as have less wisdom will employ it in meaner pursuits, and perhaps in what may be justly censured as vicious.”

Smith doubted that everyone is born with such moral instincts. He argued that individuals gained the perspective of an impartial spectator to judge their own actions via a socialisation process.

Hutcheson argues that people resent infringements of liberty:
“the sense of natural liberty is so strong, and the loss of it so deeply resented by human nature, that it would generally create more misery to deprive men of it because of their imprudence, than what is to be feared from their imprudent use of it."

Hutcheson doesn’t see any problem with persuasion:
“Let men instruct, teach, and convince their fellows as far as they can about the proper use of their natural powers, or persuade them to submit voluntarily to some wise plans of civil power where their important interests shall be secured.”

Francis Hutcheson sums up:
“This right of natural liberty is not only suggested by the selfish parts of our constitution, but by many generous affections, and by our moral sense, which represents our own voluntary actions as the grand dignity and perfection of our nature.”

(The quoted passages by Francis Hutcheson are from A System of Moral Philosophy, published posthumously in 1755, pp 293-5.)

Wednesday, September 4, 2019

How did beliefs about individual rights travel from Cicero to Locke?


This rather long post follows on from one in which I asked how we got from natural law to natural rights. In case you are wondering, the “we” referred to are people who currently have relatively broad scope to exercise natural rights to liberty. 

I concluded the preceding post by suggesting that many of the ingredients of John Locke’s view of liberty and natural rights, enunciated in the 17th century, were already present in Cicero’s account of natural law from the 1st century BC.

This post is about the ways in which beliefs about individual rights were transmitted, or evolved, over time. When people think about the transmission or evolution of beliefs and shared values it is common to have in mind a process in which books and other media are maintained or rediscovered, and thinkers reject or build on the premises of the reasoning of those who came before.

However, transmission and evolution of beliefs about individual rights can also occur as people observe the spontaneous evolution of rules of just conduct and social norms. It is possible for such evolution to occur spontaneously as “the result of human action but not human design” (to use an expression coined by Adam Ferguson, but much loved by Friedrich Hayek). Evolution of the English common law is often cited as an example of that process.

How much can be explained in terms of the spontaneous evolution of rules?

Hayek began his discussion on the classical and medieval tradition of the evolution of law by noting that even in the height of democracy in ancient Athens it was not possible to alter the rules of just conduct by a simple decree of the assembly. A change could only be brought about through a complicated procedure involving a specially elected body (Law, Legislation and Liberty (LLL), V1, p82). He also notes that classical Roman civil law was almost entirely the product of law-finding by jurists rather than legislation. (See the preceding post for Cicero’s quoting of Cato in support of that view. Hayek included that quote in Constitution of Liberty, p57). The famous law code of the Emperor Justinian was largely a collection of past laws and extracts of the opinions of Roman jurists.

Hayek argues that in the early medieval period, for about 1,000 years, law was again regarded as something to be discovered, not made. He quotes Fritz Kern:
There is in the Middle Ages, no such thing as the ‘first application of a legal rule’. Law is old; new law is a contradiction in terms; for either new law is derived explicitly or implicitly from the old, or it conflicts with the old, in which case it is not lawful” (LLL, V1 p 83).

Larry Siedentop describes how the Christian church created canon law in the 12th century by sifting through Roman law to establish which rules were compatible with Christian beliefs. Canon law covered aspects of private and criminal law including usury as well as marriage, adultery and divorce. Siedentop comments:
Little wonder that at times civil lawyers felt their domain was under threat” (Inventing the Individual, p 212).

Hayek notes that from the 13th century onwards, law making on the European continent gradually came to be regarded as an act of the will of the ruler. He suggests that was associated with the rise of absolute monarchy. England managed to preserve the medieval ‘liberties’, because of “a deeply entrenched tradition of common law” under which jurists “had developed conceptions somewhat similar to those of the natural law tradition” (LLL, V1, p 84-5). Hayek mentions the contribution of Edward Coke in defending the common law tradition against King James I and Francis Bacon, that of Mathew Hale in opposition to Thomas Hobbes.

That account almost takes us to John Locke. In his discussion of natural rights, Locke does not seem to have acknowledged the relevance to his views of the common law of England. However, as noted by Stephen Shepherd, Locke left evidence that he had read Coke and that he was influenced by near contemporaries, who had learned the law from Coke and the common lawyers. Shepherd also points out that Locke’s account of property rights has parallels in the common law (‘The Common Law and the Constitution’, American Society of Legal History, November 2005).

Spontaneous evolution via legal processes can explain how many ideas about natural rights evolved and persisted, but has limited capacity to explain recognition of natural rights of people who haven’t had standing in the courts. Judges can only discover individual rights in respect of cases that are brought before them. For example, the famous case (Somerset v Stewart) in which Lord Mansfield found slavery to be unsupported by the common law of England was decided in 1772 (many years after Locke died). The case was heard because Somerset's three godparents, from his baptism as a Christian in England, made application to the court on his behalf. Lord Mansfield narrowly limited his judgment to the issue of whether a person, regardless of being a slave, could be removed from England against their will, and said they could not.

A more fundamental limitation of spontaneous evolution of natural rights arose because in medieval times the common law was constrained by the influence of church authorities. For example, English common lawyers conceded jurisdiction to the church courts in relation to usury, defined then as "whatsoever is taken for a loan beyond the principal". The common law courts did not protect the rights of individuals to engage in mutually beneficial arrangements to borrow and lend money.

In order to understand the evolution of rules in relation to matters such as usury it is necessary to consider the evolution of reasoning about natural law.

How was Locke influenced by the evolution of reasoning about natural law?

Locke attributes the view that all are created equal “with no-one being subjected to or subordinate to anyone else” to Richard Hooker (1554-1600), an influential theologian in the Church of England:
The judicious Richard· Hooker regards this natural equality of men as so obvious and unquestionable that he bases on it men’s obligation to love one another, on which he builds their duties towards each other, from which, in turn, he derives the great maxims of justice and charity”.

Such views are, of course, central to Christianity. By mentioning Richard Hooker, however, Locke was indicating that he wanted to link his views to the symbolism of natural law which, as Linda Raeder has observed, was “a well-developed tradition of Western moral and political discourse”:
“The symbol was first advanced by the ancient Greeks, impressively elaborated by the Roman Stoics (most notably the Roman orator Cicero [106-43 B.C.]), and later incorporated into the Christian tradition as the “unwritten” law embedded in the heart of man and similar constructs. During the Middle Ages Thomas Aquinas (1225-1274), the “Angelic Doctor,” provided Christian civilization with a philosophical elaboration of the natural law that remains a characteristic element of Roman Catholic teaching to the present day” (The Nature and Purpose of Government, A Lockean View, 2017, p25).

As Larry Siedentop has pointed out, some leaders of the early Christian church recognised freedom of religion. Tertullian (c 155 – c 240) argued that “it is a basic human right that everyone should be free to worship according to his own convictions” (Inventing the Individual, 2015, p 78). Unfortunately, many of the church leaders who followed did not recognise such basic human rights.

Augustine (354 – 430) acknowledged the ethical significance of free will, and tried to strike a balance between fatalism and the belief that individuals could achieve salvation by their own efforts. He emphasised that it is important for individual Christians to develop a moral perspective, or conscience, and argued that it was the task of the church to try to create and tend consciences. Augustine’s emphasis on the importance of conscience set the scene for theologians who came much later to recognise freedom of conscience.

In the 9th century, Eriugena, an Irishman, known by his contemporaries as John the
Scot, produced a vigorous defence of free will against those who claimed the authority of Augustine for their view that “predestination applies both to good and bad” (Darrin McMahon, Happiness: A History, 2006, pp 110 – 112).

Research by Brian Tierney (discussed in Larry Siedentop’s book, pp 245-9) found the idea of natural rights to be present in 12th century canon law. Important contributions, including those of Rufinus, Odo of Dover and Hugguccio, led to a range of individual rights – overlapping those recognised by jurists in ancient Rome - being defended in terms of natural justice.
   
Thomas Aquinas (1225 – 1274) gave some recognition to freedom of conscience. He acknowledged that under some circumstances a person is justified in acting in accordance with an erring conscience, even if this entails disobeying the state. Nevertheless, he defended persecution of religious heretics.

Aquinas made an important contribution to liberty in recognising that laws exist primarily to enforce the rules of justice, rather than to make human beings virtuous (George H Smith, The System of Liberty, 2013 p 91).

Arguably, Aquinas’ most important contribution to liberty came indirectly via his Christianisation of the teachings of Aristotle. Aquinas argued that individuals can attain some happiness in this world through their natural capacity for contemplation of (religious) truth. Darrin McMahon suggests:
Aquinas’s opening up of a space in which ‘some partial happiness can be achieved in this life’ continued a process of restoring agency to the individual that had received impetus from the work of Eriugena and others during the Carolingian Renaissance” (op. cit. pp 129 – 131).

In the 13th century, John Duns Scotus argued that “an act is neither praiseworthy nor blameworthy unless it proceeds from the free will” and, in the 14 the century, William of Ockham associated reason with individual experience and choice, and saw ‘right reason’ as obligated by principles of equality and reciprocity. (I wrote about Duns Scotus and Ockham in my review of Siedentop’s book.)

In the 16th century, the late Spanish scholastics made important contributions to recognition of natural rights. Murray Rothbard highlighted the role of Francisco de Vitoria (c 1450 – 1514) who denounced the conquest and enslavement of the Indians of the New World (Economic Thought Before AdamSmith: An Austrian Perspective on the History of Economic Thought, V1, p 102). Rothbard also notes that some of those who followed Vitoria in the Salamanca school, made important contributions in defining circumstances in which the charging interest on loans was acceptable. Juan de Mariana (1536 – 1624) was the forebear of John Locke’s theory of popular consent. He held that in transferring their original political power from a state of nature to a king, the people reserved important rights, including rights concerning taxation, vetoing laws and reclaiming political power (Rothbard, op cit, pp 117-119).
 
A recent book by Ángel Fernández Álvarez points out the striking similarities between Locke’s Two Treatises on Government (1689) and Mariana’s On the King and the Royal Institution (1599). Fernández points to evidence that Locke had read Mariana’s books and that he and Mariana had the same position on the origin of property in work as well as the similar views on natural rights mentioned above.

What about Spinoza?
Baruch Spinoza (1632-1677) was a Jewish-Dutch philosopher whose views were influential, but difficult for his contemporaries to cite. In the 17th century, being accused of being a Spinozist was apparently as hazardous for an author’s claim to have views worthy of consideration as being accused to be an atheist. Spinoza held that there is only a single substance, which may be called either God or Nature, raising the issue of whether he was a pantheist, an atheist, or a "God-intoxicated man".(Anthony Kenny, A New History of Western Philosophy, p 550, 552).

The similarity between many of the views of John Locke and Spinoza has been noted by Wim Klever (Locke’s Disguised Spinozism). Spinoza argued:
“Inward worship of God and piety in itself are within the sphere of everyone's private rights, and cannot be alienated.”
Spinoza held that such “opinions fall within a man's natural right, which he cannot abdicate even with his own consent” (George H Smith, The System of Liberty, 2013, p91).

Conclusion
Beliefs and values supporting natural rights of individuals to life, property and liberty seem to have travelled from Cicero to Locke through both the spontaneous evolution of rules and evolution of reasoning about the natural law. Those different transmission processes interacted. There were periods when reasoning about natural law held back recognition of individual rights to participate in mutually beneficial activities e.g. lending and borrowing. Eventually, however, reasoning about natural law reinforced and extended individual rights recognised under common law.