This chapter discusses defences, which are a fundamental part of criminal law, and reflect important limitations on the proper scope of punishable conduct. It is the purpose of this chapter to set out and critique the law relating to defences, in both treaty-based and customary international law. This chapter is concerned with substantive defences; it does not deal with issues such as immunity, youth, ne bis in idem, or limitation periods.

In an ideal world, people who enter into contracts would choose to enter the contract, and agree to its terms, because they have accurate and comprehensive information on which to base their decision. This chapter will first explain when a contract may be invalid, because one or both parties entered into the contract under some sort of misapprehension, or on the basis of misinformation. We will look at mistake (mutual mistake, unilateral mistake and common mistake) and misrepresentation. We will also briefly explain the old action ‘non est factum’ (‘not my deed’) and the remedy of rectification. Second, the chapter will explore when a contract may be invalid because of ‘unfair’ conduct by one of the parties – for example, where one party (Party A) enters an agreement because another party (Party B) subjected A to undue pressure (duress or undue influence); or because the conduct of B is so ‘unconscientious’ or the contract is able to be set aside in equity for unconscionable conduct.

The standard way to distinguish between negligence and recklessness is in terms of the agent’s awareness of the risk he is taking. An agent who knows that there is a risk of harm is reckless, an agent who does not know (leaving aside for now whether the belief is reasonable or not) is negligent. Antony Duff argues that we should amend this slightly – What renders an agent reckless is not caring enough about a risk. Duff’s amendment suggests, very plausibly, that mere lack of awareness is not what really matters morally. What matters, rather, is why an agent is not aware. This is taken for granted in the background conditions for negligence – which, for example, should be distinguished from stupidity. An agent may not be aware of a risk because she is not cognitively capable of such awareness. The background condition for negligence is that an agent could have been aware of the risk, but is not. So if an agent could have been aware of a risk, but is not because she was too lazy to look out the window, or check her calendar, or whatever, if, in other words, the reason that she is not aware of the risk is that she does not care enough, she should count as acting recklessly rather than negligently. I argue that there is something in Duff’s view to be rescued here. The rapist who does not understand or accept sexual refusal is not reckless if he has no awareness at any level of the relevant descriptive and normative facts. However, he should not be seen as negligent either. The structure of the situation is such that his ignorance is systematic, not one off. I argue that it is an important feature of negligence that it is one off, that it is not connected to a system of oppression. This gives us a justification for moralizing the ‘reasonable belief’ requirement in sexual consent cases. Even when a belief is reasonable by epistemic standards, it may be unreasonable by moral standards. The overall point here is that in a society riven by sexism, the essential definition of rape must advert to reasonable moral beliefs rather than reasonable epistemic beliefs.

In the previous chapter, I explained that we may need to reconsider familiar formulations of fundamental principles when we apply them in new contexts. In this chapter, I ask how we might even embark on such evaluations. A traditional and commendable scholarly reflex is that we must ‘ground’ our analysis in certain and self-evident bedrock. I will show the infeasibility of this search for secure moral foundations.

I suggest a non-foundational approach, using a coherentist method: we do the best we can do with the available clues and arguments. The clues include patterns of practice, normative arguments, and casuistically-tested considered judgments. We can work with ‘mid-level principles’ to carry out fruitful analytical and normative work.

The coherentist approach accepts that our principles are human constructs, that our starting points are contingent, and that we have no guarantees of ‘correctness’. Discussion of fundamental principles is not a matter of ethical computations; it is a conversation. It is a human conversation, a fallible conversation, and nonetheless an important conversation. I also argue that coherentism offers the best explanatory and justificatory account of the method used in most criminal law theory. In other words, it is the best theory of criminal law theory.

This chapter introduces the context and objectives of the book. International criminal law is still a relatively new body of criminal law, that was constructed in a rapid transnational conversation. The time is ripe for careful systematic and normative evaluation of this corpus of law. For example, scholars have noted that some doctrines may contradict fundamental principles of justice that the system claims to uphold. The book proceeds in three steps: it explains a problem, it outlines a solution, and then it demonstrates the solution through application.

The first, preliminary, objective of the book is to demonstrate a problem. Namely, the book highlights the need for an additional type of reasoning in criminal law: ‘deontic’ reasoning, which is different from doctrinal or teleological reasoning, and engages directly with principled constraints such as the legality and culpability principles.

Second, the book outlines a method for deontic reasoning, and in particular for identifying fundamental principles. ICL poses several special challenges for identifying the appropriate principles. The book advances a liberal, open-minded, humanistic, and coherentist approach (and explains each of these features).

Third, the book dissects current controversies in command responsibility in order to demonstrate the method, its questions, and the insights it can generate.

Together with the prohibition of illegal expropriation analysed in Chapter 6, the standards of treatment examined in this chapter constitute the core of the protection conferred by international investment agreements (IIAs) to foreign investors and their investments. They protect these investors and investments against a broad range of conduct attributable to host States, sometimes in connection with the conduct of private persons. The extent and modalities of the protection granted by these standards have traditionally suffered from a lack of clarity, which has led arbitration tribunals to decide on the legal issues raised by their practical application. Beyond this lack of clarity, treaty practice has also displayed nuances and differences concerning the extent and modalities of the protection granted by those treaty standards. Although nuances and differences remain in IIAs concluded in the 2010s, States have endeavoured to clarify the extent and modalities of this protection. Chapter 5 provides in-depth analyses of the standards of treatment, focusing on treaty practice and arbitration practice as well as the evolution thereof. More specifically, it examines in turn: (1) the fair and equitable treatment standard; (2) the full protection and security standard; (3) the national treatment standard; (4) the most-favoured-nation treatment standard; and (5) the umbrella clause.

The primary source of law before the Court is the Statute itself and the principal subsidiary instruments, the Elements of Crimes and the Rules of Procedure and Evidence. The Court may also refer to relevant rules of international law, notably those of international humanitarian law and international human rights law. Article 25 of the Statute sets out the various forms of participation in crimes starting with direct perpetration but also including ordering and forms of complicity and attempt. Article 28 defines so-called command or superior responsibility, by which an individual may be held responsible for crimes perpetrated by subordinates. The Court cannot prosecute an individual who was under 18 at the time of the crime. Statutory limitation of crimes within the Court’s jurisdiction is prohibited. There is a presumption that all crimes subject to the Court’s jurisdiction require proof of intent and knowledge. Several defences are codified: diminished mental capacity, voluntary intoxication, self-defence, duress and necessity, mistake of law and mistake of fact and, under limited circumstances, superior orders.