Intro to Paralegal Studies 2025 – 400 Free Practice Questions to Pass the Exam

The substantial capacity test is a critical part of the Model Penal Code (MPC) as it assesses a defendant's ability to understand their conduct and conform their behavior to the law at the time of the offense. This test was introduced in the MPC to provide a modern approach to criminal responsibility that considers both the defendant’s mental capacity and their understanding of right and wrong. It focuses on whether the individual, due to mental illness or defect, lacked substantial capacity to appreciate the criminality of their actions or to conform their conduct to the requirements of the law.

In contrast, the M'Naghten test, the irresistible impulse test, and the necessity test are not part of the Model Penal Code. M'Naghten focuses on whether a defendant knew the nature of the act or understood that it was wrong, while the irresistible impulse test assesses whether a defendant was able to control their actions. The necessity defense pertains to situations where a person argues that they were compelled to act in a certain way to prevent a greater harm, which is a different legal concept altogether. Thus, the substantial capacity test aligns with the MPC framework, making it the correct choice.