Legal Dictionary

reasonable person

Legal Definition of reasonable person

Related terms

Definition of reasonable person


reasonable person

  1. (law) A fictional person used as a comparative legal standard to represent an average member of society and how he or she would behave or think, especially in determining negligence; sometimes formulated as "a person of ordinary prudence exercising due care in like circumstances."

Further reading

The reasonable person is a legal fiction of the common law representing an objective standard against which any individual's conduct can be measured. It is used to determine if a breach of the standard of care has occurred, provided a duty of care can be proven.

The reasonable person standard holds: each person owes a duty to behave as a reasonable person would under the same or similar circumstances.[1][2] While the specific circumstances of each case will require varying kinds of conduct and degrees of care, the reasonable person standard undergoes no variation itself.[3][4]

This standard performs a crucial role in determining negligence in both criminal law�that is, criminal negligence�and tort law. The standard also has a presence in contract law, though its use there is substantially different.

The standard does not exist independently of other circumstances within a case which could affect an individual's judgment.


  1. Brown v. Kendall, 60 Mass. 292 (1850).
  2. Franklin, at 54
  3. Triestram v. Way, 281 N.W. 420 (Mich. 1938).
  4. Franklin, at 55


  1. Wiktionary. Published under the Creative Commons Attribution/Share-Alike License.


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6.     tort law
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8.     lex causae
9.     law
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