There are several different defenses in tort law which may excuse a defendant of wrongdoing and prevent him from being held liable for damages to the plaintiff. When a tort is committed, meaning that a defendant's actions interfered with the plaintiff's person or property, a plaintiff's consent will excuse the defendant of the wrongdoing.
Although a defendant's conduct may be considered immoral, or harmful, if the plaintiff allows these interferences to occur, then the defendant is not considered to have committed a tort. Consent occurs when a plaintiff displays a willingness to participate in the defendant's conduct. It can be manifested through words or actions.
The defendant has the right to infer consent from the plaintiff's actions the way any reasonable man would. In some cases, silence and inaction may manifest consent when it is reasonable to assume that a person would speak or act if he objected to the defendant's actions. Also, if a behavior was previously consented in the past, the defendant may continue to regard this behavior as acceptable until he is told otherwise.
For example, if the defendant has been allowed on prior occasions to enter the plaintiff's home and has no reason to believe that this is no longer allowed, is not considered guilty of the tort of trespassing.
However, consent may not always excuse a defendant of liability. Sometimes consent is ineffective under certain conditions. If the plaintiff lacks the capacity to consent, is coerced into consenting, or consents under false pretenses, the consent is not valid as a defense to the tort. There is also certain types of conduct that the law considers no person reasonably able to consent to.
Incapacity exists in the cases of infancy, intoxication, or mental incompetence. The law also recognizes that a person may have the capacity to consent to some specific types of conduct, but not to others. One who is of legal age is generally assumed able to consent to all types of conduct unless this person possesses some kind of abnormality that the defendant is aware of.
The abnormality may be temporary, such as a person who is under the influence of a prescription drug, alcohol, or in a extremely tense, stressful situation. Or the incapacity may be due to a permanent factor such as a mental disease or defect. This incapacity must interfere with the plaintiff's ability to weigh the benefits and consequences of the defendant's suggested conduct.
The consent of someone who is considered incapable may be obtained by that person's legal guardian. When the courts are deciding a case in which a legal guardian consented on behalf of another, it must be determined whether that guardian had the legal right to do so and if the decision was in the best interest of the incapacitated individual.
This consent issue often arises in cases of medical procedures in which patients are unable to consent to a specific surgery that may be necessary to save their life.
A person's actions can sometimes be justified without a plaintiff's consent in the case of an emergency. A doctor has the right to offer medical attention to a patient who has been injured in an accident, without consent, under certain conditions.
The person must be incapacitated, unable to make a decision, and without the aid of a person that is legally able to consent on their behalf. If time is of the essence, meaning that the doctor must act quickly, and it can be assumed that the person would normally consent, the doctor is legally able to attend to this person without consent.
Consent is used by a defendant in order to negate responsibility for a tort. If a plaintiff consented to the defendant's actions, as long as that person is mentally capable and did not consent due to misrepresentation of the facts, no tort is committed.