20

Introduction

“The Times 03/Jan/2009 Chancellor on brink of second bailout for banks.”

^[1]This headline from the British Newspaper is encoded in the “genesis block”^[2]—the very beginning—of the Bitcoin blockchain. Amidst the chaos of the global economic crisis and the printing of extraordinary amounts of money in order to prop up an over-leveraged financial system, the pseudonymous Satoshi Nakomoto (the person or group of persons responsible for theorizing, designing, and releasing the first version of the open-source blockchain/cryptocurrency technology known as Bitcoin^[3]) placed a cryptographic hash of this headline in the genesis block as a permanent statement of disapproval toward the existing global monetary system. Nearly a decade later, advocates of blockchain technology suggest this new technological category may well become as disruptive (in the positive sense) to human society as the Internet itself.^[4] While there is much about this new technology worth engaging and questioning from an ethical perspective—not least this technology’s enormous environmental implications^[5] and the profound inequality in the distribution of its wealth^[6]—this chapter seeks to place one aspect of blockchain technology—so-called “smart contracts”—into conversation with the virtue of Justice as traditionally construed in Thomas Aquinas.^[7]

One clarification is necessary at the outset of this chapter: as will become clear in subsequent paragraphs, advocates of blockchain technologies make rather extraordinary claims about the implications of these new technologies. At the time of this publication, it is too early to tell if any of these claims will prove to be accurate, or if the passage of time will reveal the blockchain buzz to be just another form of techno-utopian fantasy. What is clear now, however, is that major financial and technological organizations are dedicating significant resources to the advancement and deployment of these technologies. Microsoft integrated the Ethereum blockchain technology into its widely utilized Azure platform in 2015.^[8] Jack Dorsey—the billionaire founder of Twitter—tweeted in 2018 that he believed Bitcoin was likely to become the world’s “single currency” within a decade.^[9] And Fidelity Investments—the asset management corporation with more than $7.2 trillion US under management—launched a custodial service for cryptocurrencies in spring 2019.^[10] My point here is simply that blockchain technologies have gone from being the niche interest of a few geeks in 2009 to major foci of major corporations in less than a decade. While I do not believe all of the expansive claims of crypto enthusiasts will prove accurate, there is enough activity in this space to warrant sustained attention from ethicists. I hope that this chapter will help extend this area of consideration.

That clarification established, let’s spend some time considering what blockchains are.

Although the first block in the Bitcoin blockchain was mined on January 3, 2009, Satoshi released the theoretical structure of Bitcoin in the “Bitcoin Whitepaper” in 2008.^[11] In the whitepaper, Satoshi suggested that Bitcoin could function as a better form of money, one that could—thanks to its cryptographic underpinnings—vastly supersede the vulnerabilities and drawbacks of traditional forms of money that depended upon centralized institutions in order to function. Without need for a centralized authority to issue, secure, or guarantee its value, Bitcoin would be impervious to traditional methods of monetary control, attack, and corruption. Instead of these institutional forms of authority, Bitcoin would function through a decentralized, globally distributed, unhackable network employing sophisticated cryptographic technologies. Bitcoin thus purported to offer a new paradigm, a new system of money that could exist outside the traditional financial world. Indeed, the whitepaper implicitly suggested that if the Bitcoin experiment gained enough users, it would prove profoundly disruptive, rendering traditional financial institutions obsolete—or at least vastly less necessary to the instant global exchange of value—by supplanting their centralized, trust-based models with these “trustless” cryptographic technologies supported by decentralized, globally distributed networks.

Bitcoin is today a flourishing, if relatively small, financial ecosystem. The total value of the Bitcoin network today is approximately $130 billion, compared to the trillions of USD in circulation.^[12] Approximately $1 billion US equivalent in value is transacted every day on the Bitcoin blockchain,^[13] and some $18 Trillion of US equivalent of Bitcoin have been transacted across the Bitcoin network to date, without a single cent unaccounted for.^[14] Satoshi’s elegant cryptographic idea succeeded in generating a viable new monetary ecosystem wherein anyone with an Internet connection is able to instantly transact and verify the validity of their transactions within the public, open-source, distributed ledger of Bitcoin’s blockchain.

Inspired by Bitcoin’s success, new blockchain projects are deployed frequently. All told, more than fifteen hundred blockchain-based cryptographic tokens have been released into the wild, purporting to revolutionize everything from identity management to land ownership, air traffic control systems to global supply chains. Indeed, blockchain is a new buzzword among many of the world’s top financiers, even as the Ethereum blockchain is being used by the World Food Programme to help keep track of aid provided to Syrian refugees at a refugee camp in Jordan.^[15] Put simply, the blockchain era is rapidly dawning and disrupting traditional sectors even as it creates new spheres of innovation.

While the angles of worthy analysis on the blockchain phenomenon are at least as varied as the problems these new blockchain implementations seek to address, in this chapter I want to consider whether blockchain technology is really as disruptive as it purports to be, a task I pursue by examining blockchain from the perspective of the virtue of justice as traditionally formulated by Thomas Aquinas. This chapter proceeds by first outlining what are purported to be especially salient aspects of the cryptographic mechanisms of blockchain technologies, followed by consideration of some of the implications these nascent technologies would have—in a hypothetical scenario wherein they succeed in substantially achieving their purported ends—on the formation of the virtue of justice within an agent who chooses to utilize such technologies in her dealings with others.

Blockchain Technology

First, a brief description of some technical underpinnings of blockchain technology, for the cryptographic mathematics upon which it is based are purported to eliminate the need for—or at least radically reconstitute the nature of—trust between people. Note that I am not here suggesting that I agree with these claims. Rather I am trying to summarize how blockchain proponents understand the technology to function in an ideal state.

Timothy May, an engineer for Intel who retired at the age of thirty-four and dedicated the rest of his life to the development of the philosophy and technology known as “Crypto Anarchism,” penned the “Crypto Anarchist Manifesto” in 1992.^[16] Describing advances in cryptographic math made practically accessible through widespread deployment of sufficiently powerful computers into the hands of larger and larger populations of people, May noted that “these developments will alter completely the nature of government regulation, the ability to tax and control economic interactions, the ability to keep information secret, and will even alter the nature of trust and reputation.”^[17] While there is much worth considering and critiquing in May’s Manifesto, I’m going to leave aside much of the libertarian and crypto-utopian implications in the first clauses of the quoted section for now, and focus specifically on the claim that cryptographic technologies are capable of altering the nature and of trust.

Proponents of blockchain technologies argue that blockchains anchor trust not in people or in institutions, but rather in asymmetric cryptographic mathematics that serves as the arbiter between people.^[18] One oft-repeated saying in the blockchain community is “Don’t trust. Verify.” Mathematic verification becomes the new form of trust, for the possibility to verify another’s claim is precisely what asymmetric cryptographic mathematics makes possible. This kind of cryptography is based upon what are called “key pairs,” consisting of a one-to-one mathematically linked private key and public key. While a few lines of code are all it takes to generate a new key pair in a few milliseconds on a smartphone, it is “computationally impractical”^[19] to reverse-compute (“crack”) the private key corresponding to a public key. So long as the private key is kept private (that is, known only to the owner/user), the cryptographic scheme is computationally unbreakable. The full weight of the known physical properties of the universe prevents the private key from being hacked: that is to say, there are approximately as many possible key pair combinations in a 256-bit public/private key pair^[20] as there are atoms in the visible universe. As such, unless someone actually knows the one and only private key that unlocks a particular public key, trying to brute force the correct key isn’t just a needle-in-a-haystack scale problem, but an atom-in-a-universe scale problem. What this means practically is that the cryptography upon which blockchains are built is unassailable with contemporary computing technology, and is likely to be unassailable into the distant future.^[21]

A critical aspect in blockchain technology is the “distributed network” of computers that comprise the ecosystem. These computers (called “miners” and “nodes”) are distributed all over the world and individually operate a software protocol that receives, validates, transmits, and records transactions within the ecosystem. These miners and nodes collectively examine and maintain the so-called “blockchain,” which is the historical record of every transaction that has ever occurred within the entire ecosystem. The miners and nodes examine and verify the blockchain and any newly proposed transactions in a consensus method based on the pre-determined rules that are built into the software protocol they are each running. The code running on this distributed network collectively acts as a decentralized arbiter between the network’s participants. No transaction that invalidates the rules of the network is accepted as valid. Any transaction that succeeds in meeting the pre-determined rules of the ecosystem is accepted and permanently recorded in the blockchain. Furthermore, because the software is open-source, any potentially nefarious code that an attacker might seek to introduce is flagged and rejected by the community before it is merged into the main code distribution. What this arrangement creates is a profoundly robust and fault-tolerant, automated, unhackable trust machine.

In Bitcoin, a public key is an address in the Bitcoin blockchain to which any amount of value within the Bitcoin ecosystem may be sent. Spending the value held in that address requires a cryptographic signature from the private key associated with that public key. If the private key is in fact cryptographically associated with the public key, the transaction is cryptographically valid, and the network of miners and nodes accepts the transaction and confirms the transfer of value between the specified addresses. Every ten minutes (approximately) a new “block” of transactions is added to the blockchain. The credit and debit to each address is then immutably recorded into the blockchain.

Satoshi’s idea—the technical ingenuity that ignited the blockchain era—was to utilize the insurmountable strength of cryptographic math so as to remove the need for trusted intermediary parties such as banks, governments, and courts for the transfer of value to occur between parties. In doing so, blockchains anchor their validity and trustworthiness not on the strength or efficacy of existing political or economic institutions, but rather on the mathematical and thermodynamic laws of the universe.

Because blockchains are immutable ledgers maintained by distributed networks, proponents of these technologies believe that many of the vulnerabilities facing traditional, centralized financial institutions are avoided. There is no building, no physical address, no monolithic entity to target and attempt to subvert. As such, there is no central point of failure. Blockchain advocates argue that the robust diffusion of blockchain technologies into distributed networks is another source of and mechanism for their trustworthiness. It is as difficult to stop a blockchain once it is up and running as it is to stop the Internet itself. If one group of computers in the network is attacked or shut down (as has happened many times), the network’s traffic is simply routed around it, in a way totally transparent to the end user. The network continues functioning.

Other blockchain projects, such as Ethereum, extend this underlying cryptographic structure into novel applications like “smart contracts.” In smart contracts, a pre-programmed function executes once certain conditions are met, with the full weight of the blockchain network acting as enforcer of the contract. For example, when a person who controls the private key of an address on the Ethereum blockchain signs a transaction with that private key, a separate smart contract built to monitor that address might release a trust fund, issue a purchase order, unlock a hotel room door, or pay for a refugee’s foodstuffs. Proponents of such smart contract blockchains argue that it is this kind of systematic enforcement of autonomous code-based agreements that will enable the “Internet of Things” to flourish (think: smart refrigerators that automatically order and pay for food when items get low, or autonomous vehicles that pay their bill at a charging station without human interaction).

While there is much more worth discussing regarding the technical accomplishments of blockchain technologies—including a thoroughgoing analysis of whether trust is actually transformed as proposed by blockchain advocates—such analysis is beyond the scope of this chapter. My purpose above was to outline the ideal case as advanced by proponents of blockchain. I pivot now to focus specifically on the implications of these technologies for a traditional formulation of the virtue of justice. My particular question is this: if they actually function as they purport to function, should blockchain technologies be considered a help or a hindrance to the cultivation of the virtue of justice?

Justice as Traditionally Articulated in Aquinas

I begin with Thomas Aquinas’s definition of the virtue of justice: “justice is a habit whereby a man renders to each one his due by a constant and perpetual will.”^[22]

Of necessity, I impose a certain critical limitation of scope. Obviously there is much contained in a robust conception of justice that exists outside the narrow realm of explicit agreements made between human agents, that is, the realm typically known as contractual justice. But, as “smart contracts” purport to be a kind of contract, in what follows, I’m only addressing this narrowly defined aspect of justice. Put differently, what someone is due in the name of justice contains the contractual obligations owed to her. But contractual justice does not fully encapsulate all that she is due, all that justice requires. (It would indeed be worthwhile to consider whether and how smart contracts might relate to a broader conception of justice, extending beyond the narrow realm of contractual justice. However, such an inquiry is beyond the scope of this chapter).

One critical way that a blockchain-powered smart contract differs from a traditional legal contract is its purported un-breachability. In a traditional contractual agreement, parties to the contract establish the terms of their agreement, including specifications for what to do in the event of breach of contract. Indeed, typical contract arrangements assume that breach is a real possibility. The contract is then signed by the parties, and becomes binding and in force. However, even once a traditional legal contract is in force it does not guarantee that the human agents will inevitably execute the contract. Breach is still always possible in a traditional contractual agreement.

In contrast, a smart contract is designed to be, and is believed to be by its participants, unbreachable. Once the smart contract is coded and activated, it will execute in the way it is designed to execute with perfect, binary precision. Once its specified conditions are met, it will deliver the specified consequences. Take, for example, a smart contract designed to make a mortgage payment on the second day of the next month. Once such a contract is generated and activated on the blockchain, the funds committed into the contract will be transferred to the lender on the specified day, no matter how potent the payees’ desire to breach the contract may become during the intervening time. Here, it is worth reiterating the mechanisms underlying blockchain technologies: the strength of the cryptography upon which blockchain technology is built is believed to guarantee that nobody—literally, mathematically, nobody—can breach a smart contract once it is in force. Governments can’t. Billionaires can’t. Banks can’t. Blockchain-based smart contracts make incorruptible contractual guarantees both technologically feasible and deployable at scale.

Assuming this holds true, what might the unbreakable assurance of a smart contract’s execution mean for the “constant and perpetual” aspect of Aquinas’s definition of justice? It would seem on the one hand that the utilization of a smart contract guarantees the “constancy” and “perpetuality” of the fulfillment of the contractual arrangements. Precisely to the degree that they are irrevocable, blockchain-based smart contracts are profound aids and supports to durably rendering what is due to the other. A person who enters into a smart contract guarantees that she will render to the other party what that party is due once the conditions of the contract are fulfilled. In this sense, utilizing smart contracts as a way of guaranteeing that one renders to the other what the other is due can be viewed as a profound aid to the habit of justice. One might even go so far as to suggest that blockchain technologically perfects justice.

But alas, it may not be so simple.

What about Aquinas’s emphasis on the “will” in the definition of the virtue of justice? In the same article quoted above, Aquinas notes:

Hence the definition of justice mentions first the “will,” in order to show that the act of justice must be voluntary; and mention is made afterwards of its “constancy” and “perpetuity” in order to indicate the firmness of the act.^[23]

As Jean Porter points out, for Aquinas, “justice is a virtue of the will.”^[24] If an action is to be ordered toward the virtue of justice, the human will must be engaged when rendering to another what the other is due. In an important way, a smart contract short-circuits the utilization of the agent’s will in following through in rendering to the other what is due: a mechanism in a distributed network autonomously activates upon pre-determined preconditions and then, and only then, is the other rendered what she is due. This seems to be a problem. For in order for the habit of justice to be perfected, it is not just that the specifications of the contractual agreement must be rendered with constancy and perpetually, but rather that the human agent must choose to act in a way that is constant and perpetually committed to the good, and, accordingly, to constantly and perpetually choose to render to the other what justice demands.

Viewed from this angle, it would seem that in a critical way smart contracts obviate the need for the human will to be engaged in the act of rendering to the other what is due, for the rendering to the other is accomplished on the blockchain, activated by the code that operates a smart contract. Smart contracts therefore not only do not perfect the habit of justice, but may actually render the formation of such a habit and disposition of justice impossible: one is not engaging the will in order to practice or perfect a disposition when one is not actually choosing to act but rather having a machine act in one’s stead. And, if an agent just has a smart contract act on her behalf instead of actually choosing to render to another what is just—well—it would seem that she isn’t shaping a habit or a disposition toward justice in any meaningful sense.

A Possible Resolution

In the arguments presented above, smart contracts are either a mechanism for perfecting the habit of (an albeit limited form of) justice by guaranteeing that what is contractually obligated is rendered to the other at the appropriate time, or it is a technology that makes the habituation of justice almost impossible because the agent is no longer responsible for actually choosing to act so as to render what is due to the other. We can’t have it both ways, so let me try to offer a possible resolution to this seeming impasse.

The resolution I’d like to propose depends upon Aquinas’s sense of the structure and operations of the human will, and also on the careful distinction he makes between remote causes and proximate ends. First, concerning the human will. In Question 83 of the Prima Pars, Aquinas writes:

But man acts from judgment, because by his apprehensive power he judges that something should be avoided or sought. But because this judgment, in the case of some particular act, is not from a natural instinct, but from some act of comparison in the reason, therefore he acts from free judgment and retains the power of being inclined to various things.^[25]

What Aquinas is getting at here is the distinctive relationship in human agents between the faculty of reason and the operations of the will, particularly as the operations of these human qualities is distinct from the operations of non-human animals. Compared to natural instinct—the form of reason non-human animals possess—human reason presents a possible course of action to the will as the most reasonable course of action in relation to the agent’s perception of the good. Summarizing Aquinas’s argument, Jean Porter notes, “The will is the capacity to desire and pursue one’s own overall existence and full development in accordance with some reasoned conception of what it means to live an appropriate or desirable or ideal human life.”^[26] This broad conceptual realm upon which the human will operates suggests that the human will possesses capacity far beyond that of non-human animals, precisely to the degree that human agents interact with a conception of the self in relation to an overall conception of the good. This broad conception of the good, which is operative in the rationality of the human agent, includes—in our particular topic of consideration—the requirements of justice.

Because the human agent is free, she must choose whether to act in accordance with what reason presents to the will as a good course of action. The human agent does not act out of necessity or compulsion on what is presented as a good course of action by reason. By contrast, non-human animals are not free to choose whether to respond or not to what their natural instinct presents to them as the required course of action. Non-human animals simply act. Recall Aquinas’s example that a sheep does not need a faculty to choose to avoid the wolf—natural instinct is sufficient for the sheep to avoid the wolf.^[27] But when a human agent chooses consistently in accordance with what reason presents as in accordance with the good and with the requirements of justice, she forms within herself the virtue of justice. To be a just person is to be habituated in choosing to do what is just. This is precisely why freedom is so central to Aquinas’s formation of virtue: it is the agent’s free choice of what is required by justice that ultimately forms the habit of justice within her. It is here that we see more clearly how the virtue of justice is a habit of the will. As Porter further explains, “A habit of the will emerges out of, and expresses itself through, a range of choices and acts through the agent’s characteristic motivations and ways of perceiving the world.”^[28] Emerging from the agent’s characteristic motivations and ways of perceiving the world, the agent chooses to act consistently with the requirements of justice. As such, the agent is habituated into being a just person.

The specific question for our line of inquiry, therefore, is whether choosing to engage in a smart contract in order to ensure that the other is rendered what she is due is in fact an action that marginalizes or obviates the engagement of the human will. One straightforward way of responding to this would be to argue that choosing to engage in a smart contract does not obviate the agent’s formation as a just person precisely insofar as the agent’s reason for engaging the smart contract is as a means of pursuing justice, and as an outworking of what Porter described above as “the agent’s characteristic motivations and ways of perceiving the world.” Indeed, engaging external mechanisms in order to render to the other what is due is something that happens all the time in human affairs without any suggestion that such a decision inhibits the formation of justice. Trusting the post office to deliver a repayment check I owe to a friend does not obviate my commitment to repaying my friend simply because I am not the one who delivers the check. When chosen as a means of rendering to the other what she is due, a blockchain smart contract is a viable way of choosing to act in conformity with the dictates of reason regarding the just action to take.

But there is another, more interesting way to go about responding to the two lines of confused reasoning presented above. This route centers on the careful distinctions Aquinas makes between remote causes and proximate ends. Joseph Pilsner’s The Specification of Human Actions in St. Thomas Aquinas^[29] is particularly helpful in interpreting Aquinas’s rather complex treatment of the relationship between proximate and remote ends, and I follow a line of Pilsner’s reasoning below.

It is important to note that at several points Aquinas insists that the moral quality of an action is specified by its proximate end, not its remote end. Were this not the case, it would be, for example, licit to steal instead of earning money in order to give the money as alms. As Pilsner argues, “although ‘earning money’ and ‘stealing’ have a distinct and easily identifiable moral character, both would have to be identified as ‘almsgiving’ if specified by the end.”^[30] Insisting that an action is specified by its proximate end allows Aquinas to maintain the ability to evaluate actions on the basis of the proximate ends toward which the actions are directed rather than the remote end toward which the action may be ultimately directed. Earning money is good. Stealing is not good. Earning money and giving alms from that money is good. Stealing and giving alms from that money is not good.

However, Aquinas does allow for the possibility that an act obtains a certain moral species from its remote end. Aquinas’s regular utilization of Aristotle’s example of a person who commits adultery in order to steal emphasizes this point. Indeed, Aquinas distills this example into a dictum: “he who commits adultery for the sake of theft is more a thief than an adulterer.”^[31] In his Commentary on Ethics Aquinas argues the point in this way: “For it is clear that if an act of vice or evil is ordered to some undue end, from this end the [act] obtains a certain new species of evil.”^[32] This particular distinction between proximate end and the remote cause of an action is insightful, but so too is another, seemingly contradictory point that Aquinas makes in the Summa Theologica. In a rather lengthy section of the Secunda Secundae that I won’t quote here in full,^[33] Aquinas makes use of the term “general cause” in such a way that allows a single human action to be specified under both its general cause as well as the proximate end toward which the action is immediately directed. Joseph Pilsner comments on this section of the Summa: “Just as the sun might be called a ‘general’ cause on account of the fact that it can illumine or change many kinds of things, so justice is called ‘general’ on account of the fact that it can direct many kinds of proximate ends to its own end.”^[34] The implications of this are that there is a simultaneous unity amidst distinction in actions oriented toward a remote end, if such a remote end requires certain proximate ends in order to be secured. As Pilsner writes, “when a proximate end is done for the sake of a remote end, it is a single human action with two ends, each of which gives its own proper species to this action.”^[35] Pilsner points to another section of the Summa, wherein Aquinas likens such a series of human actions to a geometric line: “just as line A to C is one, even if it passes through point B, so a human action from an end is one, even if it passes through a means.”^[36] The salient point here is that Aquinas seems to allow for unity amidst distinction in human acts wherein a proximate end is oriented toward a general cause.

This distinction between a “general cause” and a “proximate end” is very helpful in parsing our apparent impasse concerning smart contracts. For it is entirely conceivable that an agent would choose under the general cause of justice to engage a smart contract as a proximate end as a way of ensuring that the other receives her due. Let us consider a situation in which an agent intends to render to another what is due—she is choosing the general cause of justice—and then chooses to engage a blockchain smart contract in order to ensure that the other receives what is due at the appropriate time, when the necessary conditions have been met—the proximate end. Such a course of events does not substantively change what is required for the development of the virtue of justice—that is, consistently choosing to do what justice requires. I submit therefore that such an action is consistent with Aquinas’s traditional formation of the virtue of justice, even as the agent pursues it through the engagement of cutting-edge twenty-first century technology.

There is much more that ought to be explored concerning the relationship between blockchain, virtue, and justice. It may well be that blockchain technologies eventually change the means of human interaction as absolutely and irrevocably as the Internet has. But even if blockchain technologies do succeed in many of their purported goals, we would be wise to assume that blockchain will neither perfect nor obviate the need to cultivate the virtue of justice. For even when utilizing smart contracts, in order to be truly just, a human agent must still choose whether or not to act in accordance with the dictates of reason in rendering to the other what is due.

MICHAEL YANKOSKI is a joint Ph.D. candidate in Moral Theology and International Peace Studies at Notre Dame’s Kroc Institute for International Peace Studies. He is the author of four books, and his research explores the intersection of anthropogenic climate change, virtue theory, strategic peacebuilding, and human population displacement.