The Effect of Foundational Law on the Environment

By: Sara Robideaux

Pierson v Post, decided in 1805 and regarding an incident in 1802, is an American legal case involving property law. This case took place in the state of New York and begged the question of rights while pursuing a wild animal. This ruling is considered both foundational and essential in future property law cases.[1]

In December of 1802, Lodowick Post was attending a hunting party with friends and began to pursue a wild fox after his hunting dogs communicated a scent. Pierson began chasing this fox through a vacant lot. Although Pierson was actively pursuing the fox, he had not wounded, snared, or entrapped the fox in any way. During this time, the defendant, Jesse Pierson, also spotted the fox, killed it, and proceeded to take it. Pierson claimed that he had no knowledge that the fox was being chased by another party.[2] Following this situation, Post sued Pierson claiming trespass against his possession of the fox. Pierson felt that his action of chasing the fox, also gave him ownership rights, which Pierson violated by shooting, killing, and claiming the fox.

The question of this case was whether a person has the right to claim legal possession of an animal, of “ferae naturae” meaning wild animals of nature, while chasing it.[3] The trial court ruled in favor of Post. Following the ruling, the defendant appealed and the case was ultimately decided in the Supreme Court of Judicature of New York. The case was heard by Chief Justice James Kent, along with Associate Justices Daniel Tomkins and Henry Livingston.[4]

The court reversed the trial court’s decision and ruled that the defendant was not at fault. The court ruled that the fox, an animal of ferae naturae, is not acquired by merely chasing. This decision was based on both ancient writings and common law.[5]

Justice Tomkins delivered the opinion of the court. A key factor being that a beast of ferae naturae is acquired by occupancy only, this begs the question of what constitutes occupancy. The court used previous general principles of law and ancient writings to answer this question. Both Justinian’s Institutes, lib. 2. tit. 1. s. 13 and Fleta, lib. 3. c. 2. p. 175 provides that a simple pursuit, and even wounding, does not constitute ownership. The definition of occupancy for beasts of ferae naturae is given by Puffendorf, lib. 4. c. 6. s. 2. and 10.; for one to claim occupancy, they must have actual corporal possession. Puffendorf does elaborate that if one had mortally wounded the animal, it would prevent another from claiming possession.[6] But, considering the fox had not been wounded, Post had no right to claim occupancy. In addition, the court mentioned the common law requirement to have control over one’s possessions, a chase does not provide that. While Pierson’s actions may have been rude or inconsiderate, legally he had the right to pursue the fox. The opinion of the court also cited a case from m 11 Mod. 74—130 where there was an action of hindering or disturbing the plaintiff. Since there is a clear differentiation, as Pierson did nothing to hinder Post, again, Pierson cannot be held responsible for any crime.[7]

Justice Livingston dissented the court’s ruling. Livingston argued that by pursuing the fox, Post demonstrated control, citing that possession is relative.[8] He also felt that by giving hunters property rights, it would encourage them to continue hunting beasts in the countryside. In other words, if hunters feel that they could spend a considerable amount of time locating and pursuing an animal, just for it to be shot and claimed by someone else, it may deter them from doing so. This case is known to be the most famous ruling regarding property law because it defined ambiguous hunting laws, which proved to be essential in future cases.[9]

Although ancient, Pierson v Post has been discussed recently, thanks to Angela Fernandez in her eye-opening book Pierson v. Post, The Hunt for the Fox: Law and Professionalization in American Legal Culture, Fernandez argues that this decision affected not only what people are able to own, but what people pursue and attempt to own. She claims that the court’s decision results in overconsumption and releases incentives for consumers to take more than they otherwise would.[10]

Legal decisions not only affect the specific cases and precedents for decisions but also the overarching values of citizens who abide by them. In this case, hunters are given the idea that if they do not immediately injure or claim an animal, they will lose it to someone who will. Therefore, environmental consequences are inevitable. The World Wildlife Fund released that 23% of extinctions are caused by overhunting; the long-term effects of this are severe.[11] Due to the ancient nature of this law, it is difficult to tell if it had any significant effect on our current extinction problems, but that is definitely a possibility.

[1] Pierson v. Post, WIKIPEDIA (Sept. 18, 2021),

[2] Bloomberg Law, Pierson v. Post, CASEBRIEFS (last visited Apr. 16, 2022),

[3] Id.

[4] Charles Donahue, Jr., Establishing the Distinction Between Meus and Tuus, HARVARD LAW REVIEW (last visited April 16, 2022),

[5] Pierson v. Post, 3 Caines 175, 175-182 (1805), (last visited April 16, 2022),

[6] Id.

[7] Id.

[8] Bloomberg Law, supra note 2.

[9] Harvard Source, supra note 4.

[10] Jennifer Nadler, Angela Fernandez, Pierson v. Post, The Hunt for the Fox: Law and Professionalization in American Legal Culture, UNIVERSITY OF TORONTO LAW JOURNAL,  (last visited April 16, 2022),

[11] Rinkesh Kukreja, Causes, Effects and Solutions to Overhunting (Hunting of Species), CONSERVE ENERGY FUTURE (Aug. 2, 2020),