To access this feature, please Log In or Register for your Casebriefs Account.

Add to Library




Defenses Based on Individual Characteristics


Defenses Based on Individual Characteristics


The criminal law generally assumes that most people have common mental and psychological capabilities sufficient to hold them responsible for the crimes they commit. But the criminal law does provide limited opportunities for a defendant to avoid or lessen his responsibility by demonstrating that one or more of his important human capacities was significantly impaired when he committed the criminal act.

Defenses such as insanity, infancy, intoxication, and diminished capacity are among the more important of these opportunities. These doctrines permit a defendant to claim that it would be unjust to punish him at all or as severely as a normal person because of his unusual limitations. They are fundamentally different from defenses like self-defense or necessity, which claim the defendant did the “right thing” in the situation. The defenses discussed in this chapter acknowledge that the defendant did not do the “right thing” but that, nonetheless, other policy considerations require that he be treated differently. For this reason many courts and scholars describe these defenses as “excuses” rather than “justifications.”

The defense of entrapment is somewhat unusual. It claims that the defendant did not “really” act with the same bad attitude as a criminal. It is also aimed at making sure the police do not “manufacture” crime.


As we saw earlier, the criminal law assumes people know the law and have free will.[1] Their abilities to know and to choose (or, put in psychological terms, their cognitive and volitional capacities) are bedrock premises of criminal responsibility and underlie all philosophical theories of punishment.[2] Utilitarians expect the threat of punishment to influence behavior because people know they will be punished for breaking the law and will decide not to. Retributivists punish because defendants have chosen to commit a criminal act and have thereby earned their just deserts.[3]

Consequently, the criminal law generally does not ask whether a defendant knows if his conduct violates the law or finds it difficult to obey the law. Criminal law doctrine condones cognitive or volitional failure as an excuse in only a very few and well-defined instances.

[1] See United State v. Barker, 514 F.2d 208 (D.C. Cir. 1975) (Bazelon, J., dissenting).
[2] J. Feinberg, What Is So Special About Mental Illness, in Doing and Deserving: Essays in the Theory of Responsibility (1970).
[3] Hart, The Aims of the Criminal Law, 23 Law & Contemp. Problems 401 (1958).

Create New Group

Casebriefs is concerned with your security, please complete the following