Fernando Alvia de Castro, the true Reason of State

Oscar Pérez de la Fuente

Carlos III University of Madrid

https://orcid.org/0000-0002-3708-846X

Abstract

This paper analyses the figure of Fernando Alvia de Castro and his treatise Verdadera razón de Estado, placing it within the context of Spanish political thought in the 16th and 17th centuries. Through a commentary on various passages from the work, it examines his anti-Machiavellian stance and its connection with Tacitism, a school of thought that accepts political realism inspired by Tacitus but seeks to reconcile it with Christian morality and the principles of natural law. The text highlights the tension between theory and practice in the exercise of government, as well as Alvia de Castro’s critique of a conception of power geared exclusively towards the prince’s utility or convenience. In contrast to the pragmatism attributed to Machiavelli, the author defends a raison d’état founded on honesty, justice, equity and religion. This analysis enables us to link the debates within the Spanish Monarchy on political prudence, virtue and morality with contemporary discussions concerning the ethical foundations of power, moral scepticism and the normative limits of political action.

Keywords: reason of state, anti-Machiavellianism, Tacitism, political ethics

ISSN: 3127-3408

https://doi.org/10.67647/minervastrategy.2026.15

Fernando Alvia de Castro was born in Logroño, La Rioja, in 1572 and died in Lisbon, Portugal, in 1653. He held various posts within the Spanish Crown’s administration, mainly in the Kingdom of Portugal.

In addition to his administrative role, Alvia de Castro was the author of a short political treatise, The true Reason of State, in which he adopts an anti-Machiavellian stance, albeit one tempered by his humanist education (Peña Echevarría, n.d.). He belonged to the Tacitist movement, which emerged during the Renaissance and drew admiration and inspiration from Tacitus. This school of thought engages in dialogue with Machiavelli and accepts his realist approach to politics, while seeking to reconcile it with morality (Virtual Library of La Rioja, n.d.).

Below, I discuss excerpts from The true Reason of State by Fernando Alvia de Castro in the style of the Minerva Strategy Blog.

“Jerónimo Franchetta states that discipline, principle and knowledge—derived from the teaching of others, from reading historians and political writers, from one’s own understanding, and from experience of worldly affairs—enable the prince and his ministers to govern in whatever way best serves the prince’s comfort and benefit. In the first point he speaks the truth, but in the last he erred greatly, for he sets the prince’s comfort as the ultimate end, whereas it ought to be nothing other than the outcome arising from honesty, reason, fairness and justice” (Alvia de Castro, 1998, 135).

The first part of this reflection is entirely justified, as it addresses the key issue of the relationship between theory and practice in politics. It is important to be aware of the sources of science and philosophy, as well as the views of experts, combined with the specific lessons drawn from experience and practice. Alvia de Castro’s criticism of governing for the comfort and personal gain of the ruler alludes to the temptations inherent in the exercise of power. That the aim of government should be the ‘comfort and personal gain’ of those in power does not seem justified either politically or morally, as it must be based on ‘honesty, reason, fairness and justice’.

“I return to the definition of the affairs of state and conclude by saying that, in the case of a good Christian prince, it is a wise discourse, a course of action and execution in accordance with divine law and natural reason, whereby, to the extent of human knowledge, matters are arranged so as to bring about favourable, yet just, outcomes for the prince and his states. For, as Aristotle teaches, the prudent person must wisely determine the end of his actions” (Alvia de Castro, 1998, 139–140).

This approach may be read as an expression of natural law, as a theory of law, and of flexible monism, as a way of understanding the relationship between politics and ethics. From this perspective, morality and politics overlap: politics must remain subject to moral criteria. In the history of ideas, there is controversy over what the principles or rules of morality—normative ethics—should be, and over what their foundations—meta-ethics—are. As can be inferred from Alvia de Castro’s text, in his day the foundations of morality were sought in classical sources, such as Aristotle, and in Christian authors, such as Augustine of Hippo. Indeed, an influential political interpretation of his religious work The City of God gave rise to the ‘two swords’ theory: the sceptre, representing secular power, was to be subordinate to the crozier, representing religious power. This was the prevailing political doctrine in the West during the Middle Ages, and there is some debate as to whether it still holds true today in various contexts.

“I also cease to call it prudence because, according to Pontano, it is not a virtue; and if reason and the virtue of what is just, lawful and good are lacking in matters of state, such prudence will be erroneous, false and open to criticism, given that the term ‘prudence’ is also applied to vices and evil things” (Alvia de Castro, 1998, 140).

Two models of prudence are contrasted here in terms of political rationality. On the one hand, Machiavelli’s political realism leads to a form of pragmatism according to which, if the prince achieves his objectives, the means he employs will be praised. On the other hand, the doctrine of true raison d’état—of which there are several versions—generally maintains that political objectives must remain compatible with morality, in line with natural law and flexible monism.

“And, with regard to this aspect of true religion and moral virtues—which is the main theme of my discourse and the true substance of statecraft—it is necessary to point out how wrongly and falsely certain bad politicians spoke of him, and in particular the perverse, impious and ignorant Machiavelli” (Alvia de Castro, 1998, 147).

The interpretation of the ‘Machiavellian’ Machiavelli is presented here as synonymous with immorality and contrary to religion. There are other interpretations of this figure which view him as a patriot from the perspective of the ‘republican’ Machiavelli. The key point is that theories of the true raison d’état criticise the Machiavellian perspective on the basis of morality or religion, with some nuances. It is noteworthy that, as Abellán points out in his work History of Spanish Thought, anti-Machiavellian activity was to prove pivotal in the history of Spain and was likely to constitute one of the fundamental reasons for Spanish ‘dissent’ from the rest of Europe (Abellán, 1996, 231).

“He argues, then, that a Christian prince should possess such a command of the virtues that he knows how and is able to change his ways and act contrary to them; and that, in order to preserve his kingdom, he will be obliged to act against faith, charity, humanity and religion as it suits him (…) And, in essence, he sets out and constructs the image of a hypocritical, false, dissembling and insincere prince. And, although this proposition is so manifestly erroneous, blasphemous and false, let us nevertheless refute it with reason and doctrine” (Alvia de Castro, 1998, 147).

During the period in which Alvia de Castro lived, conceptions regarding the foundations of ethics and normative ethics were strongly influenced by references to Classical Antiquity and by Christian authors. In the West today, metaethical positions advocating moral scepticism have gained considerable prominence; according to these, there are no intersubjective moral values, which can lead to the postmodern ‘anything goes’ attitude. The key issue is how to ground ethics so that it serves as a sound guide for those in power and provides a basis for judging their actions.

References

Abellán, José Luis (1996), Historia del pensamiento español. De Séneca a nuestros días, Espasa, Madrid.

Alvia de Castro, Fernando (1998), “Verdadera razón de Estado”, en Castillo Vegas, Jesús et al. (eds.), La razón de Estado en España. Siglos XVI-XVII (Antología de textos), Tecnos, Madrid, pp. 131–148.

Peña Echevarría, Javier (n. d.), “Fernando Alvia de Castro”, Real Academia de la Historia, available:

https://historia-hispanica.rah.es/biografias/2077-fernando-alvia-de-castro

(accessed: 23 July 2026).

“Alvia de Castro, Fernando, 1572-1653”, Biblioteca Virtual de La Rioja. Available:

https://bibliotecavirtual.larioja.org/bvrioja/es/consulta_aut/registro.do?id=227

(accessed: 23 July 2026).

Vegetius: trust, effort and expectations

Oscar Pérez de la Fuente

Carlos III University of Madrid

https://orcid.org/0000-0002-3708-846

Abstract

This article examines several rules of war formulated by Vegetius and interprets them as principles of strategic action beyond the strictly military field. The analysis focuses on the importance of accurate information, strategic advantage, effort, expectations, confidentiality and surprise. Vegetius’s reflections show that successful action depends not only on strength or resources, but also on the ability to assess one’s own position and that of the opposing party with precision. In this sense, concepts such as BATNA and ZOPA help translate classical military insights into contemporary strategic and negotiation contexts. The text also highlights the role of hard work and disciplined habits as conditions for success, as well as the importance of positive expectations in shaping action and influencing others. At the same time, it stresses the need to control the information shared with opponents and to protect strategic plans from premature disclosure. Finally, the element of surprise is presented as a way to prevent the other party from preparing an effective response. Overall, Vegetius’s work remains valuable because it offers practical lessons on trust, effort, prudence and strategic judgement.

Keywords: strategy, expectations, negotiation, military tactics

ISSN: 3127-3408

https://doi.org/10.67647/minervastrategy.2026.14

In this post, I will continue to analyse the rules of war set out by Vegetius in the Compendium of Military Tactics, interpreting them with a view to their strategic application in other areas.

g) Having as much accurate information as possible about the other party – and about our own side – is the key factor (Vegetius, 2006, p. 310, III.XVIII).

Vegetius’s ninth rule of war states: “It is difficult to defeat someone who is able to make an accurate assessment of their own troops and those of the enemy” (III.XXVI).

This relates to the need to have the best and most comprehensive information about the parties in order to make a decision. It is also linked to how the ZOPA (Zone of Possible Agreement) is defined in each situation – whether one actually has the necessary information to assess each party’s real options. This also means that all information and communication from the other party must be analysed and verified impartially.

h) Sometimes the strategic advantage is a given 

The tenth rule of war states that “courage is of greater help than the number of soldiers”. And the eleventh states that “position often provides a greater advantage than courage” (Vegetius, 2006, p. 310, III.XVIII).

Applied to other areas of strategy, one could say that strategic advantage stems from a better BATNA – the best alternative to a negotiated agreement.  But even in such situations, it is possible to engage in negotiation and explore common interests.

i)Hard work brings success; idleness does not

The thirteenth rule of war states: ‘The army thrives on effort, but is ruined by apathy”  (Vegetius, 2006, p. 310, III.XVIII).

This is linked to the view that hard work is more likely to lead to success than apathy. It is connected to habits and dispositions that shape character, which are known as virtues. If one works hard and practises these virtues, one eventually becomes virtuous.

j) Expectations are the key

The fourteenth rule of war states that “you must never lead a soldier into open battle unless you see that he has a chance of victory” (Vegetius, 2006, p. 310, III.XVIII).

This is excellent advice. You must expect to win if you want to succeed. In many situations, the key lies in our own expectations and, above all, in the expectations others have of us. If you are striving to achieve a goal, you must have the highest expectations and convey them to others, while still taking impartial information into account.

k) Be careful about the information you provide to the opponent

Vegetius’s twenty-eighth rule of war states that “when you realise that your plan has been revealed to the enemy, it is advisable to change your tactics” (Vegetius, 2006, p. 311, III.XVIII).

The information you provide to your opponent should be limited to that which works to your strategic advantage. It is important to know exactly what they actually know about your plans. You should interact with them in such a way as to convey only what works to your advantage.

l) Don’t reveal your plans to just anyone

The twenty-ninth rule of war states that “consult many people on what ought to be done, but consult only a very few whom you trust completely – or, better still, only yourself – on what you are actually going to do” (Vegetius, 2006, p. 311, III.XVIII).

It is important that, once the strategic objectives have been defined, the specific ways of actually achieving them – the detailed action plan – do not necessarily need to be made public. It is important to consult trusted experts to test ideas against their views. However, it is not wise to shout the action plan from the rooftops. A distinction must be made between deliberation and the actual taking of decisions.

m) Do not let your opponent prepare their defence against your predictable attack

Vegetius’s thirty-third rule of war states that “the enemy must not know how you intend to conduct the battle, so that they do not attempt to put up resistance by taking appropriate measures” (Vegetius, 2006, p. 311, III.XVIII).

This is the strategic advantage of the element of surprise: opponents prepare their defences for the points where they believe they will be attacked. This, for example, calls for creativity in devising various options and using arguments that have not been widely explored. The awkwardness of the situation may lead them to improvise a response, which can involve making concessions to the other party.

It can be concluded that Vegetius’s Compendium of Military Technique is a classic work on military strategy and also offers important lessons: the best way to tackle a situation is with confidence, hard work and a positive outlook.

References


Vegetius Flavius Vegetius Renatus (2006), Compendio de técnica militar, Cátedra, Madrid, trans. David Paniagua Aguilar.