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  • Lewis Waring

The Reasonable Person - Ramsay Hall

The purpose of this paper is to critically analyze the reasonable person standard that is used as an objective test in many criminal law contexts, such as assessing the mens rea in offences that impose objective liability like dangerous driving or determining whether the accused may successfully rely on self-defence to obtain an acquittal. This paper will begin with a brief overview of what the reasonable person standard is, and I will assert that a standard of reasonableness is essentially identical to a standard of intelligence. I will then explore a few examples that showcase how the definition of this standard is regularly in debate and its application frequently inconsistent.

This leads to the principal question that this paper is trying to answer: why is it seemingly impossible for the reasonable person standard to remain stable, and is there a better alternative standard that could be used in its stead? Ultimately, I will find that the reasonable person standard is inherently arbitrary and unfair which is why there is a constant (but futile) push towards changing its definition. Despite this, I will explain that there are powerful policy reasons as to why the reasonable person standard should be preferred to any other standard that could be used as an objective test.


Although the concept of the reasonable person standard goes back at least to Ancient Rome, its first appearance in the common law was in the English case Vaughan v Menlove (“Vaughan”) in 1837. Vaughan established that the reasonable person standard must be completely objective and that the trier of fact must avoid considering any of the defendant’s subjective attributes, such as intelligence.

Before I examine how this standard has changed, I must first postulate that a standard that measures according to the actions of a hypothetical reasonable person is identical to a standard that measures according to the actions of a hypothetical intelligent person. I am not sure how controversial this idea is, but to me it seems self-evident. The ability to reason coincides with the ability to think, which is necessarily dependent upon the thinker’s capacity for thought, i.e., their intelligence. Other words often used in place of “reason” in Canadian law, such as “prudent”, are also essentially synonyms of “intelligent”. Therefore, when courts apply a reasonable person standard, they are in essence applying a standard of intelligence.

Throughout this paper, I will be using the terms reasonable and intelligent interchangeably. My contentions in this paper are not dependent upon the fact that they actually are completely equivalent; that the two concepts undeniably overlap to a large degree is sufficient.

The changing standard

Since its initial articulation in Vaughan, the exact definition of the reasonable person standard has frequently been in a state of flux. In 1993, R v Creighton established that the reasonable person test for objective mens rea offences must adhere to a “single, uniform legal standard” and avoid considering any personal characteristics of the accused, with the sole exception being where those personal characteristics result in the incapacity to appreciate risk. However, in 2019, the majority in R v Javanmardi partially reversed this by considering the accused’s skill and expertise as part of the objective test thus rendering the test more subjective.

The reasonable person standard does not only vary in its definition, but it also varies in its use. In 2017, R v Berry inconsistently employed the standard in that the intelligence of the accused was considered as part of the objective test for the defence of self-defence but not as part of provocation’s objective test. I find this inconsistency to be quite concerning. The law should mandate consistency between the reasonable person standard for different objective tests, especially between two similar defences. Predictability and dependability are important considerations in forming the law, and inconsistencies generally detract from those factors.

Another issue that presents itself is that, if a standard of reasonableness is the same as a standard of intelligence, then considering the accused’s intelligence as part of the reasonable person standard means that the standard is being measured against itself. In such a case, the test loses any semblance of objectivity and becomes purely subjective.

The final issue that I have with the reasonable person standard’s inconsistency forms the focus of the rest of this paper. That final issue explores the origins of the reasonable person standard’s lack of stability and consistency.

Inherent unfairness

At first blush, an objective standard seems to necessarily connote impartiality, and thus it should be easy for different parties to agree on a definition. Of course, given the tumultuous legal history of the standard, this is obviously not the case. The simple explanation for this discrepancy is that the reasonable person standard is not impartial: measuring someone against a standard of reasonableness, i.e., a standard of intelligence, is blatantly unfair to those who possess, through no fault of their own, a lower measure of reasonability or intelligence.

The following statement from Justice McLachlin in Creighton summarizes the general theory behind the reasonable person standard: “the mental fault lies in the failure to direct the mind to a risk which the reasonable person would have appreciated”. In other words, if someone behaves less reasonably than a person possessing normal reasonability would have, they have thereby done something wrong and may be punished for it. There may be a reason to find fault in some situations, such as when a highly reasonable person is careless or overlooks something and in so doing behaves unreasonably. But should someone who possesses minimal intelligence and thus rarely considers the consequences of their actions, especially the long-term consequences, really be considered to be at fault? If it is commonplace or normal for someone to behave unreasonably, in comparison to a person possessing a regular degree of reasonability, and this person acts unreasonably in a particular situation, have they really done anything blameworthy?

An analogy

Imagine if there was a fire alarm placed high up on a wall. Suppose that, whenever there was a fire, everyone in the vicinity had a duty to ring it. Should a person who is too short to reach it be punished for not ringing the alarm? Practically everyone would answer no to this: why should someone be punished for something that is outside of their control? I’m sure that the average Canadian would also find it ridiculous were I to claim that they should be punished based upon the notion that “the physical fault lies in the failure to direct the hand to a height that a person of ordinary or reasonable stature would have reached”. So if height is analogous to intelligence in that it is beyond a person’s control, then it must also be absurd to punish an unreasonable person for failing to be reasonable enough. Are they analogous?

One argument against their analogousness is that, while intelligence may be beyond one’s control in a general sense, in specific instances it is possible to be more reasonable by “trying harder”, i.e., by purposefully directing one’s mind towards the potential consequences of a given action. This, it could be argued, is clearly not applicable to height, as one cannot make an effort to grow a little taller in a given situation. Thus, height and intelligence are distinguishable in this manner.

It may be true that, with effort, one can try to be more thoughtful or reasonable in a particular situation. However, this is extremely limited. A person who is poor at math may put great effort into studying, and do their utmost to fully concentrate on their math quiz, and yet, they can still perform below average. Effort can lead to improvement, but it is no guarantee of successfully meeting any particular standard. Indeed, the same actually applies to height. That is, a particularly short person actually could put effort into reaching the fire alarm by standing up straight or by jumping, but, at the end of the day, they may still be too short.

Small changes in perceived height or intelligence may be possible in certain situations, but the fact is that people do possess differing amounts of various attributes, and these amounts are largely invariable at the time they are being judged. Whether these differences are due to genetic factors, environmental factors, or some combination of the two is irrelevant. The key point is that, at the moment where fault would be imposed, no large degree of change is possible. A person could potentially take measures in the future to change their attributes; probably, they could have taken measures in the past to change them. However, at the present moment when they are being judged on their adherence to an objective standard, there is little to nothing that they can do.

Since the reason behind not imposing fault on someone who is too short to reach the fire alarm was that they did not have any control over their ability to reach it, fault should not be imposed in any scenario where one has no control over their ability to meet a given standard. Thus, if the above analysis is correct, fault should not be imposed on someone who does not behave in a reasonable manner through no fault of their own.

In conclusion, I suspect that the frequent variation of the reasonable person standard is a result of people, including lawmakers and judges, realizing that there is an element of inherent unfairness in holding unreasonable people to a standard of reasonability. The pushes towards modifying the objective test by making it more subjective are the result of lawmakers trying to avoid punishing people for qualities outside of their control; the pushes back towards a “purer” objective standard are a result of lawmakers realizing that introducing subjective elements nullifies an objective standard’s purpose, namely, to have a clear measuring stick against which liability can be easily, quickly, and consistently determined.

There are many arguments for and against the usage of an objective standard in criminal law, and it is outside of the scope of this paper to determine whether it should be used. I want to end this paper by arguing that, despite all of the above, the reasonable person standard is in fact the best objective standard possible. This is, of course, not because it is less unfair than any other standard. Rather, there are strong policy reasons to favour it over any alternative.

The best available standard

Why is reasonability the standard used in an objective test in the first place? I am going to present two possible reasons. The first reason why the reasonable person standard exists may be because it originated out of the self-interest of judges and other lawmakers. There is no doubt that the average judge is more intelligent than the average person and as such is capable of a greater degree of reason. Therefore, if liability for negligence, for example, is determined based on whether one acted at least as reasonably as an ordinary person then it should be easy for a judge to reach this level of reasonability and thus rarely be found liable for negligence. By decreeing that persons must be judged according to a reasonable person standard, the judge largely protects himself from being found liable as he himself will rarely be found to be lacking in reason relative to an average person.

This, of course, would not be a good reason for continuing to use the reasonable person standard. However, there is a second reason that can better explain the longevity of a standard that is so inherently unfair and can also justify its continued use.

Public perception

That reason is that, although in reality a mental standard is just as unfair as a physical standard, the public perceives the mental standard to be significantly less unfair than a physical standard. A greater perception of fairness leads to greater faith in the judicial system, which leads to greater legal/political stability. If this doesn’t explain the origins of the reasonable person standard, it likely at least explains its durability.

Why does the public perceive a mental standard to be less unfair than a physical standard? The two main reasons are belief in free will and human arrogance.

Firstly, the average person adheres to what is essentially Cartesian dualism, i.e., a belief that there is a fundamental distinction between the mind and the body. From this perspective, the body is purely physical and control over it is greatly limited whereas the mind is what actually constitutes the person, thoughts and feelings being under his or her direct control. This topic is far too complex to delve into at a deeper level, but I think it suffices to say that the average person believes that there are fewer limits on the brain than there are on the body. This assumption grounds a belief that a standard based on the ability to change the brain allows for greater personal control and thus greater fairness.

Secondly, while the average human can see whether someone is taller or shorter than them and can state with reasonable accuracy who actually is taller or shorter than them, they cannot do the same with regard to another’s mental faculties. This allows for substantially more delusional arrogance with regard to one’s own mental attributes in comparison to one’s own physical attributes. In 1977, faculty at the University of Nebraska-Lincoln were surveyed, and 94% rated themselves as possessing an above-average teaching ability. Would 94% have deemed themselves to be of above-average height? Of course not. Another example is in the famous Dunning-Kruger effect, whereby the average person in the bottom quartile of intelligence considers themselves to be of above-average intelligence.

The fact that differences in mental attributes between people are mostly hidden from an easy or simple comparison thus frequently gives rise to an overestimation of one’s own ability. As a result, a large majority of people believe that they will benefit from being measured against a person of average reasonability. This may not be the case, at least not to nearly the same extent, for a standard based on a visible physical characteristic.

Ultimately, the public’s belief in free will and control over one’s mental faculties, combined with their tendency to overestimate their own mental ability relative to the average, brings a widespread perception that the reasonable person standard is substantially fairer than a physical standard. This results in greater public faith in the judicial system, which leads to many societal benefits like an increase in political stability. Therefore, there are important policy considerations that should lead us to prefer the usage of a mental standard over a physical standard as an objective test.

Reasonable person standard imperfect but justified

The reasonable person standard that is currently used as an objective test throughout many areas of Canadian law is inherently unjust, as would be any other standard that could possibly replace it. Perhaps we should therefore jettison entirely the usage of any sort of objective test. However, if there are strong enough reasons to continue to use an objective test, the reasonable person standard is what should be used; not because it is any less unfair than any other standard but because it is perceived as less unfair than any other standard, and this results in a legal system that inspires greater happiness, harmony, and stability.


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