The Ten Criteria

What are the Ten Criteria for Human Personhood?

They are the seven criteria for biological life plus three more criteria specific to human people.


1. Organized Structure

2. Metabolism

3. Growth

4. Response to Stimuli

5. Homeostasis

6. Reproductive Capability

7. Evidence of Adaptation Through Evolution

8. Human Genetic Code

9. The Ability to Think Thoughts

10. The Ability to Feel Emotions


To be fair and just, a criteria for the start of person's life must also make sense in the context of death. The Ten Criteria for Human Personhood achieves this distinction. When your brain ceases to function—that is, when your brain ceases to have the ability to think thoughts and the ability to feel emotions—your life as a person ends. Likewise, when your brain gained those abilities, your life as a person began.

The Ten Criteria for Human Personhood were carefully balanced to include all indisputable peopleincluding babies, disabled people, and unconscious people—while excluding individual human cells, which were problematically counted as people by Noonan’s genetic criterion.

If you don't accept the Ten Criteria for Human Personhood as the legal definition for human person specifically because it protects elective abortion rights up to 23 weeks gestation, we earnestly ask you, what is the motivation behind legally forcing people to treat a living thing that does not have the ability to think thoughts or feel emotions as a person?

If you have a serious answer, let us know through the contact form, but first, please make sure your answer isn't one we've already addressed by looking over the following four pages: Home, First Question, Guidelines, and Responses to Anti-Abortion Arguments.

From our perspective, we earnestly perceive the notion that "an entity that does not have the ability to think thoughts or feel emotions ought to be treated as a person" as a belief based on imagination, not science. The definition of life is not equivalent to the definition of person. Neither is the definition of human equivalent to the definition of person.


There are significant discrepancies between those three definitions—life, human, and person—such that we believe the root cause of disagreement on the morality of abortion is the improper conflation between those terms. Words have meaning, and most people don't learn new words by reading the dictionary; they learn by asking someone nearby what the word means. Specifically, relating to the field of political science, we believe improper conflation of terms is a significant instigator of political disagreement.


Regarding abortion, we believe society's tendency to colloquially use the terms life, human, and person as synonyms is the reason the abortion debate not only exists but exists contentiously. The first two terms, life and human, are categorical labels from the field of biology. Life is a label applied to any entity that meets the seven biological criteria for life. Human is a label primarily applied to living things—cells, tissues, organs, organ systems, and organisms—with human genetic code. The third term, person, however, is not a biological label. Person is a philosophical label for which society has never quite come to a universally accepted definition. We coined the Ten Criteria for Human Personhood not only to bring resolution to the abortion debate but also to fill a void in the field of philosophy. If the "human genetic code" criterion is excised from the Ten Criteria for Human Personhood, then the result, the Nine Criteria for Personhood, can be a satisfying, universally applicable definition for personhood (especially in consideration of questions about the negative impact of speciesism). If you accept either the Nine or Ten criteria for personhood, please sign Respect People's petition on and feel free to leave a comment as to which set of criteria, Nine or Ten, you prefer.