The concept of personhood is widely involved in biomedical ethics discussions about abortion, stem-cell research, euthanasia, etc., though it is not always discussed explicitly. It also has other philosophical and legal relevance.

Some thinkers use the term “person” in such a way that one is either a person or not, but the situation is not that simple. It will be useful to distinguish among different types, contexts, or meanings of personhood: moral, metaphysical, physical, and legal.

Moral personhood

The moral sense of personhood denotes individual beings who are moral agents. Moral agents engage in behavior that can be evaluated as moral or immoral, as morally right or wrong, as morally permissible or morally impermissible. Their acts are blameworthy or praiseworthy. It makes sense to hold them morally responsible for their intentional actions.

Ordinarily, human beings are considered moral agents and moral persons. Nonhuman animals, such as dogs, cats, birds, and fish, are commonly held not to be moral agents and not moral persons. A lion in the jungle killing another animal to eat, or killing a human for whatever reason, is not held to be engaging in morally impermissible or blameworthy behavior. Pet-owners often scold their pets for engaging in certain undesirable types of behavior, such as urinating on the carpet, digging in the garden, or failing to obey a command, but a scream of “bad dog” is not usually considered to imply moral agency. One could argue, though, that there are some rudiments of moral expectation or anthropomorphism involved on the part of the owner.

Moral personhood might also be held to include, in a very loose sense, being a moral patient, that is, a being who can suffer at the hands of wrong actions by moral agents. Moral agents are usually moral patients, and some use the term “moral agent” to include moral patiency. But being a moral patient is distinct from being a moral actor, and nonhuman animals as well as humans are held to be moral patients. Rocks and stones, for example, clearly are not. Moral patiency is clearly not sufficient for moral personhood, and it is debatable whether it is even necessary.

The philosopher Peter French talks of a corporation as a moral person, meaning not that it is a physical or metaphysical person or that it is human, of course, but that it can be considered a moral agent and held accountable for its actions. One might think of such an entity (a corporation, a team, a group, a society, a nation, etc.) as an artificial person, but one could also say that is it plain and simple a moral person because we treat it as a moral agent and praiseworthy or blameworthy on its own. In ordinary discourse we commonly talk of corporations doing good and bad things, as if they should be held accountable for their actions, which does seems to imply we think of corporations as moral agents.

Metaphysical personhood

Metaphysics can be characterized as the study of the nature of reality, in its most basic forms or categories, such as discussion of whether everything that exists is physical (material), or whether there are two ultimate kinds of irreducible stuff, mind and matter. Sometimes the term “metaphysics” is taken to refer to a transcendent realm beyond the physical. But modern secular philosophers commonly talk of personhood in a metaphysical sense without implying the existence of any such transcendent realm.

The concept of metaphysical personhood would be to use personhood as a basic category of reality encompassing beings of a certain type: rational, moral agents, using language, etc. There is no consensus about the exact criteria. Adult human beings are commonly considered persons, and a very interesting question to ask yourself is that of exactly what it is about us that makes us persons. Clearly not having a particular hair color, or even having hair, or being a particular height, or weight, or having a brain, etc. Here are some suggested commonly-suggested criteria:

  • Rationality or logical reasoning ability
  • Consciousness
  • Self-consciousness (self-awareness)
  • Use of language
  • Ability to initiate action
  • Moral agency and the ability to engage in moral judgments
  • Intelligence

Does having one or more of the above make us a person? Do we have to have all of them? Can we have some minimal set? Does it have to be the same set for all persons?

We commonly say a human being is a person even while asleep or unconscious, for instance, even though at that moment the individual is not exhibiting all the criteria necessary for attributing personhood. Rather the individual has to have the disposition or capacity to exhibit such features.

Some people (materialists or physicalists) believe that human beings are purely physical and that the mind is just an elliptical way of referring to the brain, with any immaterial soul an old wives’ tale or religious superstition. Others (property dualists) believe that there are mental properties that are not reducible to physical properties, or (dualists and idealists) that we each have a mind that is not simply the brain, it is some sort of nonphysical stuff or substance. Others go further and believe that apart from the physical body and the nonphysical mind there is a further immaterial soul. (Some equate the mind and soul.) Those who believe the mind and/or soul are not reducible to the physical body would hold that they are essential to metaphysical personhood. They might even refer to the transcendent soul or mind as the metaphysical person.

Physical Personhood

Physical personhood per se is a concept rarely discussed by ethicists because all the heavy lifting is usually done by the notion of metaphysical personhood.

As mentioned above, materialists or physicalists believe that a human being is essentially a physical being, with no metaphysically distinct soul or mind. On this view, physical personhood and metaphysical personhood are going to be pretty much the same thing.

Dualists or idealists believe that human beings are more than just the physical, with the involvement of a metaphysically distinct mind or soul. On this view a human being on earth inhabits a physical body, possesses a physical body, or possesses an apparently physical (but really not) body, so one this view one could interpret physical personhood as just the way a person has a continuing presence in this world through the physical body. Perhaps life continues after natural death as the metaphysical person or some aspect of it continues on.

Legal Personhood

The law often recognizes that certain groups of individuals can be considered as a unit, an actor, a legal person. This sort of legal personhood allows the unitary group, for example, a corporation, to enter into contracts and engage in other legal matters as if it were a natural person. To most thinkers, useful as this is, it is an artificial type of person and not metaphysically significant. Corporate personhood may be a very useful legal concept without necessarily implying anything about corporations being metaphysical persons.

Persons and Human Beings

It is common to assume “person” and “human being” mean the same thing, but from what has been described above, this may not be true and in fact most philosophers distinguish between these two types of entity.

“Human being” is a biological designation for those of the species Homo sapiens (or related). Many thinkers hold that a person may or may not be a human being, and a human being may or may not be a person. This may sound very odd to you at first, but please pay attention to how we are using these terms.

For example, in the future imagine that we learn of aliens living on another planet, and these aliens, though not human, behave much as we do, are highly intelligent and rational, use language, talk of moral responsibility, etc. We might grant they are persons, they just aren’t human persons because they aren’t homo sapiens. On the other hand imagine an individual who loses a large amount of brain functioning. Kept alive through ventilators and artificial nutrition and hydration, this unfortunate human being might be considered no longer a person. Such examples are meant to show that we may not be using the concepts of human being and person to mean exactly the same thing.

Most individuals believe we owe other human persons obligations, such as the duty not to harm them, or that human persons possess certain natural moral rights, such as the right not to be murdered. The question arises as to whether these duties and rights stem from such human persons in virtue of their being persons or because they are humans. Many thinkers believe it is because they are persons, that is, a certain moral status depends on a metaphysical status of personhood. On the other hand, some thinkers instead believe it is because human persons are human that they possess such rights and are owed such obligations.

Complicating the question is the fact that we might believe nonhuman animals to have some rights, be owed some obligations, and have some moral status as moral patients. One might claim that they have the right not to be gratuitously tortured, for instance. But they are not persons. So if one believes this and also holds that moral rights accrue to human persons because of their personhood, then it must be that this is the case for only some rights, because nonhuman animals who are not persons have some moral rights too.

Further consider the view that special treatment is owed human persons in virtue not of their being persons but in virtue of their being human beings. One might hold this view to be a kind of prejudice, a “speciesism” (in the words of Peter Singer), that can be compared to racism.

A commonly accepted principle of biomedical ethics is respect for autonomy. This is sometimes called respect for autonomy of persons or considered an aspect of respect for persons. One should consider the question of whether “person” here was chosen over “human” for a reason and whether it means the same as or different than “human.” It’s not just an historical question but one of the present intention in upholding this principle with such wording.

Relationship among the various concepts

It may be that in our reasoning we assume the presence of some sense of personhood is required for an entity to have a certain status or property. This may have relevance for controversies in biomedical ethics, such as in abortion, stem cell research, and euthanasia. For example, some people consider the embryo or fetus to have a certain moral status of possessing a right to life and base that not only on it being human but on it being considered a (metaphysical) person from the time of conception. Others disagree with the claim that the embryo is a person at all because it fails to meet what they consider necessary criteria of personhood.

Degrees of Personhood?

Along with the questions of which criteria we consider necessary for personhood (to be a person you must have them), and which we consider sufficient conditions of personhood (if you have them then you are a person), one might come to the conclusion that personhood might come in degrees. That is, there can be partial persons and one individual is more of a person than another. This might seem nonsensical, but consider the possibility of aliens from another planet that seem to be between chimpanzees and human beings. Are they persons or not? It might be hard to say and we might allow they are partial persons. The same might occur if nonhuman animal species evolve to such an extent that we recognize them as having some kind of personhood. At what point did they gain it? Along the way were they partial persons? Or consider the example of a severely brain damaged individual, clearly still a human being, but possibly not fully a person in the metaphysical sense.

The same questions arise when we consider the ordinary development of human beings from conception through infancy and into adulthood. At what point does an individual become a person, metaphysically and morally? Some would say at conception, some would say while an embryo or fetus, others would say at birth or shortly before, while still others would say during infancy or as the infant becomes a young child. But it might be difficult to point to one moment in time when an individual went from nonperson to person, and perhaps there is room here for the concept of partial personhood.