Stem Cells

Church Teachings

The Church has always taught that the intentional direct killing of innocent human beings is morally EVIL and that “no one can claim for himself the right directly to destroy an innocent human being.”


According to the NATURAL LAW (rule of conduct prescribed to us by God), known through the light of reason (man’s ability to think and know), a human being is a “unified totality.”

Human nature is “at the same time corporal (bodily) and spiritual.” The human body cannot be thought of as just a mere complex of tissues, organs, and functions, nor can it be evaluated in the same way as the body of animals; rather it is a constitutive part of the person who manifests and expresses himself through it.

“An intervention on the human body affects not only the tissues, the organs and their functions, but also involves the person himself on different levels.”

Through REVELATION, the Magisterium of the Church also confirms that “from the moment of conception (meaning the first moment of biological development), the life of every human being is to be respected in an absolute way because man is the only creature on earth that God has wished for himself.”

The spiritual soul of each person is “immediately created by God” and his whole being bears the image of the Creator. Human life is sacred because from its beginning it involves “the creative action of God.”

Further, human procreation requires on the part of the spouses “responsible collaboration with the fruitful love of God.” The gift of human life must be actualized in marriage through the specific and exclusive acts of husband and wife.

Thus violations of the inherent dignity of human beings are IMMORAL. There exist acts which are in and of themselves, regardless of circumstances, always seriously wrong by reason of their object.

Examples of such acts include “whatever is hostile to life itself, such as any kind of homicide, genocide, abortion, euthanasia and voluntary suicide.” Additional examples are “whatever violates the integrity of the human person” (mutilation, torture) and whatever is offensive to human dignity (slavery, prostitution, trafficking).

Likewise, contraception, the use of abortifacients (including the “morning after pill”), in vitro fertilization (and the use of other artificial reproductive techniques), the freezing of spare IVF embryos, genetic engineering, surrogate motherhood, and prenatal diagnosis are inherently immoral.


The intentional and direct killing of all innocent human beings by means of abortion has always been formally condemned by the Church. This teaching has never changed.

Moreover, what is clear in the Church teachings is that the fact of being a human being is sufficient reason to proscribe abortion: “Human life is sacred,” Pope John XXIII recalled. “From its very inception it reveals the creating hand of God.”

“From the moment of conception, the life of every human being is to be respected in an absolute way because man is the only creature on earth that God has ‘wished for himself’ and the spiritual soul of each man is ‘immediately created’ by God.”

As will be noted shortly, the term conception has now been so deconstructed to mean “implantation,” especially in the law, that it is now very problematic, as is the term fertilization and the phrase natural death.


The issue of when the immaterial human soul (and thus personhood) is initially present in the early human being has been a source of some disagreement in the tradition, leading to different conclusions and impacting several related bioethics issues, especially abortion and human embryo research. Some argue for immediate personhood, others for delayed personhood. But the Church has consistently held that the critical criterion remains the fact that there is a human being present, based on teachings of the human being’s unitary nature.

Some people try to justify abortion by claiming that the result of conception, at least up to a certain number of days, cannot yet be considered a personal human life.

But, in fact, from the time that the ovum is fertilized, a life is begun which is neither that of the father nor the mother; it is rather the life of a new human being with his own growth. It would never be made human if it were not human already.

In other words, even if the presence of a spiritual soul cannot be ascertained by science, science does show us when the human being’s life begins and, because we know the human being is a unified totality, we must ask ourselves how could a human individual not be a human person?

The Church has always taught and continues to teach that the result of human procreation, from the first moment of its existence, must be guaranteed that unconditional respect that is morally due to the human being in his or her totality and unity as body and spirit.

  • Hylomorphism: A human being is not composed of two different substances (dualism), but rather is a single individual composite substance of a rational nature
  • The rational soul is not a “thing” itself separate from the human body or vice versa
  • The material body and immaterial soul of a human being must always exist coextensively from the beginning of a human being’s existence
  • The word person does not refer just to the rational part of the soul, nor to the whole soul alone, but to the entire composite human substance

If there is a human body whose cells possess 46 chromosomes (give or take) and specifically human cells, tissues, and organs continuously unfold, then there must also simultaneously be a human soul that is directing those specifically human biological functions and activities. Thus, from the beginning of his or her existence, the human embryo is a person, whose rights and protections may not be violated for any greater good.


The use of living human embryos (through 8 weeks post-inception) and fetuses in destructive research is hardly new. However, especially as human embryos became available through in vitro fertilization and other techniques, their exploitation has dramatically increased.

Regardless of legality, the Church states that “the use of human embryos or fetuses as an object of experimentation constitutes a crime against their dignity as human beings who have a right to the same respect owed to a child once born, just as to every person.”

This moral condemnation “also regards procedures that exploit living human embryos and fetuses—sometimes specifically ‘produced’ for this purpose by in vitro fertilization” either to be used as biological material or to provide organs or tissue for transplants in the treatment of diseases.

“The killing of innocent human creatures, even if carried out to help others, constitutes an absolutely unacceptable act” (Pope John Paul II, Evangelium Vitae 1995, par.63).

The same is true for the use of human embryos for the production of embryonic stem cells. Nor is it morally licit to use embryonic stem cells or their progeny supplied by others, as this would constitute formal or material cooperation in evil.

At the level of human rights, the possibility of human cloning represents a violation of the two fundamental principles on which all human rights are based:

The principle of equality among human beings and the principle of non-discrimination.

“If human rights are to mean anything, at anytime, anywhere in the world, then surely no one can have the right to do such a thing (clone). Human rights flow from the recognition that human beings have an intrinsic dignity that is based on the fact that they are human. Human embryos are human, even if they are cloned.”

Not only does human cloning violate the inherent dignity and human rights of the cloned embryo, it also “objectifies human sexuality and turns the bodies of women into commodities.” Women are also deprived of their innate dignity by “becoming suppliers of eggs and wombs.”

Universal Declaration on Human Rights, Article 3: Everyone has the right to life

International law guarantees the right to life to all, not just some, human beings and adds that involuntary medical and biological experimentation on human beings is morally wrong.

Human cloning also “poses great threats to the rule of law” by enabling those responsible for cloning to select and propagate certain characteristics such as gender or race and eliminate others. This would be akin to the practice of EUGENICS leading to the institution of a “super race.”


Violations of the dignity of early human beings are usually accompanied by the use of erroneous science and deceptive language in the attempt to justify these immoral actions.

The use of contrived RHETORIC to refer to the newly created human embryo or fetus is now extensive.

Politicized terms such as “spare” or “left-over” embryos or “products of conception” are often used.

Further rhetoric includes the false distinction between therapeutic and reproductive cloning.

As noted previously, the term conception has now been falsely redefined as beginning at implantation rather than fertilization, even in the law.

Yet new and ever erroneous scientific claims and linguistic rhetoric continue to confuse and darken consciences.

What is needed, the Church recognizes, is a cultural transformation. In particular, “There is a need for education about the value of life from its very origins.”