In 2005, Archbishop Favarola of Miami wrote the following article. It is an amazing article for its clarity and readability. He writes:

In talking about stem-cell research, it is very important to make distinctions.

Most people associate stem-cell research with human embryos. They incorrectly assume that one is not possible without the other. They infer, then, that because the Catholic Church opposes research using stem cells from human embryos, we oppose all stem-cell research and even the progress of science itself. Worse, they say we demonstrate no compassion for those suffering from the debilitating illnesses that such research could cure. Nothing could be further from the truth. The church supports ethical stem-cell research and our living tradition supports science. Throughout the centuries, many priests and religious have devoted their lives to scientific studies, including Gregor Mendel, whose research provided the basis for our modern understanding of heredity and genetics.

A stem cell is a relatively unspecialized cell that can do one of two things: make another cell like itself or make any number of cell types in the body with more specialized functions. This second activity is critical in the development of our bodies as we grow and is central to the ability of our organs and tissues to regenerate and heal. For example, just one kind of stem cell in our blood can make new red blood cells, white blood cells or other kinds, depending on what the body needs.

Most stem-cell research today involves cells obtained from adult tissue, umbilical cord blood and other sources that pose no ethical dilemma since they do not entail the killing of human beings. Adult stem-cell research has already yielded actual treatments for conditions such as Parkinson's disease, spinal cord injury, sickle cell anemia, heart damage and corneal damage. Bone-marrow transplants to cure leukemia are an example of the successful results already achieved with adult stem cells.

In stark contrast, embryonic stem cells are harvested by a procedure that destroys live human embryos. Experiments have shown that, even though they are able to make virtually any kind of cell, embryonic stem cells are extremely unstable, readily cause uncontrolled tumors and have yet to lead to any beneficial application in any human patients.

This experimentation with embryonic stem cells is what the church opposes, because it entails the direct destruction of innocent human life. That is a moral evil that cannot be brushed aside even when the laudable goal of alleviating the suffering of others is invoked.

The reasoning that these embryos are "going to die anyway" is also absurd. We will all die anyway. That does not give others the right to kill us. In opposing embryonic stem-cell research, the church is not choosing the lives of embryos over suffering patients. We are called to respect them both. In other words, we must help those who are suffering-and the church witnesses to this in many ways-but we may not use a good end to justify an evil means.

The choice is not between science and ethics, but between science that is ethically responsible and science that is not. History is rife with examples of failures to properly channel research and the terrible, broad social repercussions that follow.