Here are five modern arguments I have heard in favor of a true monarchy (or even at least a constitutional monarchy) not based upon arguments from Classical philosophy.
I don't have complete sourcing for the people who have advocated these positions right at hand (mostly because it comes from books that aren't on the Internet and not in my office), although I've provided links where I can.
Overall, these suggest that monarchy may be particularly desirable on a relative basis in societies with great scarcity where it is a second best option in situations where better options may be unattainable due to lack of resources or lack of societal cohesion. Although others have interpreted the data differently and see the transition from monarchy to democracy coinciding with the relative importance of property and labor to that historical moment's economy, with an economy in which property is the primary driver favoring monarchy.
This also fits with the notion described as a finding of the World Values Survey that societies with scarcity and uncertainty tend towards traditional and survival oriented values and often authoritarian government.
1. The Secular Value Of A Clear Succession
One important issue is succession. Monarchy allows for a clear succession with minimal expenditure of resources (compared, for example, to an election which can be expensive and can often have a hotly disputed outcome in close cases, especially in the face of corrupt bureaucracies).
Often the fact that a clear succession maintains the legitimacy of the regime and thus prevents civil wars and insurgencies can be more important that the quality of the leader who takes office. Avoiding the disruptive bad option of a disputed succession is more important than maximizing the upside by having the best of all possible leaders.
Unity behind a possibly mediocre leader can be more beneficial than disunity, when the costs of disunity are high and the potential upside of excellent v. unexceptional leadership in the political context may be modest.
This isn't just an abstract concept. For example, in the Arab Spring of the early 21st century*, all of the monarchies of the Middle East and North Africa (none of which are full fledged democracies) weathered unrest with minimal disruption, while non-monarchies saw massive societal disruption (often without achieving the hoped for objectives of democracy and more modern governance).
The linked paper is: Victor A. Menaldo, "The Middle East and North Africa’s Resilient Monarchs" 74(3) Journal of Politics (July 2012 late revised December 12, 2012). The abstract is as follows:
This paper helps explain the variation in political turmoil observed
in the MENA during the Arab Spring. The region's monarchies have been
largely spared of violence while the "republics" have not. A theory
about how a monarchy's political culture solves a ruler's credible
commitment problem explains why this has been the case. Using a panel
dataset of the MENA countries (1950-2006), I show that monarchs are
less likely than non-monarchs to experience political instability, a
result that holds across several measures. They are also more likely
to respect the rule of law and property rights, and grow their
economies. Through the use of an instrumental variable that proxies
for a legacy of tribalism, the time that has elapsed since the
Neolithic Revolution weighted by Land Quality, I show that this result
runs from monarchy to political stability. The results are also robust
to alternative political explanations and country fixed effects.
Economist Tyler Cowen touches on the succession argument here. Marc Hodak also makes the succession argument. As Hodak explains:
[P]rimogeniture did not evolve as a way to select a certain quality of
leader; it evolved as a way to enable society to accumulate capital.
For most of history, it was extremely difficult to preserve and grow
capital from one generation to the next. Before the 19th Century, the
lives of ordinary people–how they labored and what they had in their
homes–were virtually indistinguishable from that of their
grandparents. Things were hardly better among the aristocracy. For
them, accumulated property was basically an invitation to plunder.
Consequently, from the Fall of Rome to the Industrial Revolution, the
vast majority of capital created by the upper classes was in the form
of weaponry, and most of that was consumed in battle. It was in this
neo-Hobbesian war of all against all that primogeniture evolved as a
way to select kings.
The customary transfer of allegiance of powerful nobles from their
king to a royal heir greatly reduced the odds of a civil war.
Societies that tended to avoid civil war tended to accumulate far more
capital. More capital made them more powerful, economically and
militarily, creating a dynamic that eventually led to the institution
of monarchical succession via primogeniture spreading throughout most
of the world.
There is also, however, a good argument to be made that primogeniture itself is not essential and that a system of succession comparable to that of the Saudi monarchy, in which a sitting ruler and the class of potential heirs to the throne choose a successor from the monarchs many descendants based upon merit, is a better compromise between clear succession and avoiding mediocre leaders that the primogeniture solution.
2. The Efficient Use Of Scarce Educational Resources
A prince without letters is a Pilot without eyes. All his government
is groping.
Another argument for monarchy begins from the common observation in political science that politics is a mix of power and choice. Part of politics is acquiring the power to rule, and part of politics is making good choices once you have the power to implement those choices (and, of course, the two aspects of politics are not unrelated).
According to Game of Thrones aristocrat Tywin Lannister, through which George R.R. Martin espouses his carefully considered modern thoughts on monarchy against the historic background of a twisted version of European history, the qualities of holiness, justice, and strength ultimately pale in comparison to wisdom.
In many circumstances, having someone who is competent to make good choices is more important than resolving policy disputes within the pool of people who are competent enough to make good choices.
But, the education and training necessary to make someone competent to be a good political leader for a country is expensive. This may take a couple of decades of formal education, access to scarce opportunities to serve in an apprentice role to existing political leaders, and decades of developing social ties and leaning the personalities of the key players.
In a poor country, it may not be possible to meaningfully educate more than a small percentage of the population, or to give a real quality education to more than a handful of people. Recall that in the High Middle Ages (12th-century Europe) even many aristocrats wouldn’t be able to read.
A monarchy's allocation of educational resources may be arbitrary, but a country whose leaders, at least, can read and are reasonably well educated and informed, is probably better off than one in which no one is singled out for special treatment and there are no potential leaders who are literate and well educated.
In that situation, monarchy is efficient because it allows the entire country to maximally benefit for its scarce resources expended to train someone to be a good ruler because you know that one of those handful of people will actually put that training to use to make good choices for the country.
This was basically the "business model" of the Jesuit religious order in early modern Europe (the milieu in which it came into being). As explained in this Wikipedia link:
The Jesuits' contributions to the late Renaissance were significant in
their roles both as a missionary order and as the first religious
order to operate colleges and universities as a principal and distinct
ministry. By the time of Ignatius' death in 1556, the Jesuits were
already operating a network of 74 colleges on three continents. A
precursor to liberal education, the Jesuit plan of studies
incorporated the Classical teachings of Renaissance humanism into the
Scholastic structure of Catholic thought.
In addition to teaching faith, the Ratio Studiorum emphasized the
study of Latin, Greek, classical literature, poetry, and philosophy as
well as non-European languages, sciences and the arts. Furthermore,
Jesuit schools encouraged the study of vernacular literature and
rhetoric, and thereby became important centres for the training of
lawyers and public officials.
The Jesuit schools played an important part in winning back to
Catholicism a number of European countries which had for a time been
predominantly Protestant, notably Poland and Lithuania. . . .
Jesuit priests often acted as confessors to kings during the Early
Modern Period. They were an important force in the Counter-Reformation
and in the Catholic missions, in part because their relatively loose
structure (without the requirements of living in community, saying the
divine office together, etc.) allowed them to be flexible in meeting
the needs of the people at the time.
It is believed that as a response to the varying Protestant
reformations against the Catholic Church, Pope Paul III gave formal
approval to St. Ignatius of Loyola to lead this order. This order was
the most influential, intellectual Counter-Reformation by the Catholic
Church. They were most notably marked by their ability for
intellectual influence and debate among the aristocracy of Europe.
Of course, the allocation of educational resources argument can be generalized to include not just monarchy, but also entire feudal aristocratic systems.
This kind of strategy is visible, for example, in the elite Swiss educations of Thailand's recently deceased monarch, and North Korea's current de facto hereditary monarch Kim Jong Un, both of which were at the time those leaders were educated very poor economically.
This justification, however, isn't undisputedly accurate. There is evidence that even in low income countries, absolutist governments give rise to slower economic growth than democracies and to less educational progress for the masses, suggesting that absolutists actually make poorer choices despite their special access to training and education.
3. Embodiment Of National Pride And Autonomy
Countries with functional monarchies (e.g. Thailand and Japan) have tended to be more effective at asserting their national identity in the face of efforts at colonial intrusion into their culture, than nations without monarchies. See, e.g., this book discussing the connection between Thailand and its Buddhist cultural identity. A discussion of the role of the Japanese monarchy in creating and protecting an autonomous Japanese culture can be found here.
This is attributed to several factors:
Having a visible public spokesperson for the national identity who can build national pride while also modeling flexibility in the face of changing circumstances in the way that disembodied traditions and scriptures cannot.
Providing a focal point of national unity that reminds people of their commonality with each other and their differences from outsiders.
Providing a figure who has the moral authority to resolve political conflicts between powerful political figures who would otherwise act as if they were entirely unsupervised and had full impunity to act as they wished, without reminders of their need to respect the national interest.
Providing someone who can coordinate negotiations with would be colonial powers who has a longer term vision for the national well being than an elected political leader with a limited term.
A notable modern fictional work exploring these kinds of benefits is the manhwa (i.e. Korean graphic novel) called Goong, which explores in depth over twenty-seven volumes and a parallel television series, how Korea might be different (and for the most part, better), if it had retained its monarchy as Japan did, rather ending in 1910 in association with the Japanese occupation of Korea.
On the point of making elected official behave, consider this comment on the role of a constitutional monarch:
This is a relatively minor point in the scheme of things, but it's
worth briefly extolling the virtues of constitutional monarchy.
Generally speaking, in a parliamentary system, you need a head of
state who is not the prime minister to serve as a disinterested
arbiter when there are disputes about how to form a government — say,
if the largest party should be allowed to form a minority government
or if smaller parties should be allowed to form a coalition, to name a
recent example from Canada. That head of state is usually a figurehead
president elected by the parliament (Germany, Italy) or the people
(Ireland, Finland), or a monarch. And monarchs are better.
Monarchs are more effective than presidents precisely because they
lack any semblance of legitimacy. It would be offensive for Queen
Elizabeth or her representatives in Canada, New Zealand, etc. to
meddle in domestic politics. Indeed, when the Governor-General of
Australia did so in 1975 it set off a constitutional crisis that made
it clear such behavior would not be tolerated. But figurehead
presidents have some degree of democratic legitimacy, and are
typically former politicians. That enables a greater rate of
shenanigans — like when Italian president Giorgio Napolitano schemed,
successfully, to remove Silvio Berlusconi as prime minister due at
least in part to German chancellor Angela Merkel's entreaties to do
so.
Napolitano is the rule, rather than the exception. Oxford political
scientists Petra Schleiter and Edward Morgan-Jones have found that
presidents, whether elected indirectly by parliament or directly by
the people, are likelier to allow governments to change without new
elections than monarchs are. In other words, they're likelier to
change the government without any democratic input at all[.]
A closely related monarchist argument is that a monarch can be an advocate for liberty and other unrepresented interests in society because unlike a politician, a monarch is beholden to no one. As explained in this Wikipedia link:
British-American libertarian writer Matthew Feeney, on the occasion of
the birth of Prince George of Cambridge, the potential future king of
the United Kingdom of Great Britain and Northern Ireland, in 2013,
wrote:
“In the last hundred years many European nations have experienced
fascism, communism, and military dictatorships. However, countries
with constitutional monarchies have managed for the most part to avoid
extreme politics in part because monarchies provide a check on the
wills of populist politicians. European monarchies--such as the
Danish, Belgian, Swedish, Dutch, Norwegian, and British--have ruled
over countries that are among the most stable, prosperous, and free in
the world. Constitutional monarchs make it difficult for dramatic
political changes to occur, oftentimes by representing traditions and
customs that politicians cannot replace and few citizens would like to
see overthrown."
Another 21st century monarchist apology ticks off these main points along the same lines:
"as Serge Schmemann argues in The New York Times, monarchs can rise above politics in the way an elected head of state cannot. Monarchs represent the whole country in a way democratically elected leaders cannot and do not. The choice for the highest political position in a monarchy cannot be influenced by and in a sense beholden to money, the media, or a political party."
"in factitious countries like Thailand, the existence of a monarch is often the only thing holding the country back from the edge of civil war. . . . If the restoration of the erstwhile king of Afghanistan, Zahir Shah, widely respected by all Afghans, went through after the overthrow of the Taliban in 2001, perhaps Afghanistan would have more quickly risen above the factionalism and rivalry between various warlords."
"monarchies prevent the emergence of extreme forms of government in their countries by fixing the form of government. . . . The presence of kings in Cambodia, Jordan, and Morocco holds back the worst and more extreme tendencies of political leaders or factions in their countries."
"monarchies have the gravitas and prestige to make last-resort, hard, and necessary decisions — decisions that nobody else can make. For example, Juan Carlos of Spain personally ensured his country’s transition to a constitutional monarchy with parliamentary institutions and stood down an attempted military coup. At the end of the Second World War, the Japanese Emperor Hirohito defied his military’s wish to fight on and saved countless of his people’s lives by advocating for Japan’s surrender."
"monarchies are repositories of tradition and continuity in ever changing times."
"monarchies can serve up a head of state in a more democratic and diverse way than actual democratic politics. Since anyone, regardless of their personality or interests, can by accident of birth become a monarch, all types of people may become rulers in such a system. The head of state may thus promote causes or stir interest in issues and topics that would otherwise not be significant[.]"
Many of these points are reiterated in a column at Reason magazine.
4. Monarchs Favor Smaller Government Than Republics
Hans-Hermann Hoppe, a scholar at the conservative political-economic Mises Institute, argues that monarchies have a longer time horizon than republics because monarchs can pass on the kingdom to their descendants, while elected officials do not, and that this reality is intertwined in some manner with the notion that monarchies tend to involve smaller government and lower taxes.
For what it is worth, this is probably misreading history. The default position in monarchy, a la Saudi Arabia, is no taxation and no representation, with all government financed out of the personal funds of the monarch who owns the nation's greatest assets personally.
But, the predominant reasons historically that monarchs have allowed for representation of some interests other than their own (e.g. prior to the French Revolution and in connection with the formation of the British Parliament) is because they need to successfully raise revenue in the form of taxes in order to govern effectively, and therefore had to make concessions that involved the consent of the governed in order to obtain tax revenues.
Thus, it isn't that monarchs favor small government, but that monarchs who favor big government have to make concessions to finance big government because they can't afford it solely from their personal funds.
A book length treatment of this thesis by Hans-Hermann Hoppe is available for free online at the link.
There is also a more empirically motivated economic case for monarchy:
In a 2007 study, Harry van Dalen, economist at the Dutch University of
Tilburg, attempted to determine the effects of a royal head of state
on real GDP growth. Comparing World Bank data from constitutional
monarchies with other forms of government, he concluded that, on
average, the presence of a royal house accounts for 0.8 to 1.0
percentage points of additional economic growth. According to van
Dalen, a ruler in a constitutional monarchy adds stability,
efficiency, and social capital in the form of trust.
Another interpretation of that data, however, is that a constitutional monarchy only arises in a state that has had a long period of regime continuity and a history of stable democratic government, and that these factors compared to unstable or newly democratic states, is what really accounts for the economic benefits.
Contra Hoppe, however, others argue that monarchy and mercantilist economic systems go hand in hand, on one hand suppressing the tyranny of inferior nobility in the monarchs efforts to consolidate power, and on the other, suppressing free trade until smugglers become heroes. Thus, this analysis sees the economic benefits of monarchy as merely transitional. Other scholars agree with this position.
5. Advancing The Church, Recalling Historic Utopias, And Creating Hierarchy
Modern Russian monarchists emphasize the complementarity of a monarch and the Russian Orthodox church in bringing a moral compass to society, and also harken to the perceived glory of the Romanov dynastic era of their history from which the feel the nation has fallen to a lower level. This falls short of an argument from divine right, however, to a more utilitarian argument that a monarch better advances the modern church than a republican form of government.
Likewise, the Islamic State argues for a Caliphate (i.e. an Islamic form of monarchy) in part, on the theory that this would end the separation of church and state and endow the state with the moral clarity and lack of corruption. This moral clarity and lack of corruption is found to some extent in religious Islam where ISIS rules, but it is woefully absent from the secular governmental institutions that ISIS subjects have seen in their lives.
An expressed goal of ISIS is to return to the Islamic world the glory of the early Islamic empire. And, indeed, at its peak, the Islamic Empire was one of the largest (spanning from Morocco and Timbuktu to Indonesia), most affluent, and most enlightened empires the world had ever known (for example, advance mathematics, medicine, philosophy and art and preserving classical knowledge) at that point in history. On the other hand, the would be Caliphs have not shown much inclination towards restoring the tolerance and freedom of inquiry that had thrived in the Islamic empire at its peak.
In the same vein, monarchists argue with some credible behavioral and psychological support that humans, on average, have a natural desire for an orderly hierarchy:
In a 1943 essay in The Spectator, "Equality", British author C.S.
Lewis criticized egalitarianism, and its corresponding call for the
abolition of monarchy, as contrary to human nature, writing, "Where
men are forbidden to honour a king they honour millionaires, athletes,
or film-stars instead: even famous prostitutes or gangsters. For
spiritual nature, like bodily nature, will be served; deny it food and
it will gobble poison."
Certainly, it is notable that in an age where we supposedly value democracy and abhor authoritarianism and the hereditary principle, our literature for both children and adults is chock full of European princes, princesses, kings and queens, despite the fact that almost all of the remaining absolute monarchs are in Islamic countries or Africa or both.
Similarly, the Christian Bible and liturgy tell their story in a frame of royalty and aristocracy with congregants constantly reciting their allegiance to the "Lord".
Footnote: A Notable Modern Critique On Monarchism
George R.R. Martin's "Game of Thrones" series, which is based loosely on a milieu modeled on the War of the Roses (comparisons to Richard III and Henry VI are further spelled out here).
Some reviewers have described this series (in both its TV and book forms) as fundamentally, at the thematic level, a cautionary tale about all of the evils associated with hereditary monarchy as the institution has been sanitized to leave only "harmless" symbolic constitutional monarchs in the place of the absolute monarchs of old. It does so by highlighting just how much brutal and violent harm can come from unchecked arbitrary power vested by heredity in a truly bad king (exemplified by the Mad King and Joffrey), and the fact that monarchy is not necessarily a guarantee of a seamless transition. In short, it demonstrates vividly the manner in which monarchy can be bad.
Others see it as a cautionary parable urging us to be wary of a resurgent neofeudalism with corporate lords and wage serfs, returning solely to a monarchy-like political economic model.