Culpability (Mens Rea or "guilty mind")

Mens rea is a term typically used in criminal law to define the mental elements that one must possess to be guilty of a crime.

It is also used in making moral judgments in determining whether a person is actually responsible for (culpable of) a moral transgression.

For example, let us assume that a person hooks up a car so that when somebody tries to start the car it sets off a bomb in a nearby building. The car owner, unaware of this tampering, gets in the car and tries to start it. The bomb goes off, killing a group of innocent bystanders. Is the person who starts the car guilty of murder?

The standard answer is that she is not. Yes, she turned the key that detonated the bomb that killed the people. However, being guilty of a crime also requires certain mental elements – that she had some reason to suspect that turning the key would set off the bomb.

These factors are not only relevant to the criminal charge of murder but to the moral charge as well. In the absence of any reason to suspect that her actions would cause harm, she has not acted immorally.

If a store shelf gets bumped and an item falls unknowingly into bag that a customer is carrying and the customer leaves the store with it, he is not a thief. If the brakes on a car fail and the driver crashes through a fence, the driver is not a vandal.

Furthermore, in morality as in law, we recognize a distinction between the murderer who aimed a gun known to be loaded at a person, flips off the safety, and squeezes the trigger - as opposed to the agent who accidentally fires a round on a shooting range hitting another customer unintentionally.

These illustrate just a few ways in which mental elements play a significant role in judgments of criminal and moral culpability.

The link here should not be surprising. In spite of the popular slogan that it is wrong to legislate morality, laws against murder, theft, rape, fraud, and the like - in fact almost all of the criminal law - aim to enforce moral principles. The major difference between a just and unjust law rests on whether morality identifies a law as legitimate or illegitimate.

Four Categories of Culpability

Typically, law recognizes four categories of culpability.

1. Intentional/Purposeful. A person’s act is intentional or purposeful if the agent actually sought to realize the end in question. If the assassin aims a gun and pulls the trigger seeking to kill a person, then this is intentional homicide.

2. Knowing. A person knowingly acts to realize a state of affairs if he is aware of the fact that the act will realize a state of affairs, though does not specifically aim to bring it about. For example, a demolition company demolishes a house knowing that there are people inside. They did not plan to kill anybody - but they did not let the fact that their act would kill people get in the way of blowing up the building.

3. Reckless. An action is reckless when the agent knows that there is a risk of others being harmed. A person who fires a gun randomly down the street might not harm anybody. However, he creates a risk, so his actions are reckless.

4. Negligent. An action is negligent when a person ought to have known that there was a risk of harm. A drunk driver may believe that he can get home safely. However, the fact that he is not aware of the risk he is creating does not absolve him of guilt. A concerned individual would have known of the risk and would have acted differently in the face of that knowledge. In this case, the drunk driver is negligent.

Morality recognizes these same distinctions. In fact, the recognition of these states in the law follows the moral distinction. They are included in the law in order to capture a particular part component of our moral judgments.

To see what culpability aims at, let us look at a thought experiment:

Let us assume that Person A creates a device that allows him to control Person B’s body. While he is in control, he has Person B take a weapon, go to Person C's house, aim the weapon at Person C and fire.

Let us ask, who is guilty of this murder? Is it Person A - the person who aimed the gun and pulled the trigger? Or is it Person B, the one whose mental elements motivated the murder? Or do they share responsibility?

The standard answer is that A is guilty. B is innocent - he was a tool, just like the gun and the bullet were tools. A gets 100% of the responsibility, while B gets none of it.

That is to say, the culpability applies entirely to the agent who provided the mental states (the mens rea) does not apply at all to the agent who performed the physical action.

Of the various mental states, what does culpability aim at?

If a person walks into a open garage and walks out with a set of power tools, what "culpable belief" could the agent actually have?

Beliefs are certainly relevant to culpability. If the agent believed that the garage and the power tools were his, he can offer an excuse of false belief to save himself from condemnation and punishment for taking the tools.

However, the belief is relevant because of what it implies about the agent's desires. A person is not expected to have an aversion to walking into his own garage and using his own tools. However, he is expected to have an aversion to taking the property of another without consent. The person who takes tools from a garage that he could not possibly believe is his own and takes the tools, with no reason to believe that the owner gave consent, lacks such an aversion. Once this has been established, we know that the agent is morally and - where the law follows morality - legally culpable.

This, then, is where we find mens rea or the "guilty mind" - in desires of the agent. In this case, it is in the absence of an aversion to taking the property of another without consent that people generally have many and strong reasons to promote.

In closing, I would like to add that this is yet another area where desirism - the view that morality aims primarily at the evaluation of malleable desires - best explains and predicts our moral practices. The defense of desirism does not rest on its ability to rationalize our moral prejudices - that very legitimacy of that process is open to question. It rests on the theory's ability to explain the elements of our moral practice such as "mens rea", "excuse", praise and condemnation, and the like. Here, we see that the practice of searching for "mens rea" in assigning culpability can be understood as a quest for the desires that motivated an act and whether they are desires that people generally have reason to promote or inhibit.