It is scientists who have demonstrated that the single cell, or zygote that results from fertilization, contains the complete genetic information necessary for the development of a unique human being. It is scientists who have shown us that human development is a continuous, uninterrupted process, from zygote, embryo, fetus, infant, child, to adult.
These prevailing scientific opinions, they go on, are consistent with Church teaching.
We are persons whether our reasoning skills are developing or deteriorating, whether we are in the beginning stages of life or nearing life’s end.
We are not seeking to “impose” narrow doctrinal beliefs, but rather to “propose” reasonable standards for the protection of human life and dignity.
The resources linked at the Wisconsin Catholic Conference website include a press release and a 14 minute video. The pastoral letter was covered in the May 1, 2008 Milwaukee Catholic Herald, Bishops' stem cell letter spotlights 'timeless Catholic teaching'. Perhaps it has been or will be discussed in some homilies.
P.S. The bishops tried to bolster their argument with this analogy.
Furthermore, raising moral concerns is essential for genuine scientific progress. Consider the infamous biomedical case of the Tuskegee Syphilis Study. Even after penicillin was discovered in 1947, medical researchers working for the U.S. Public Health Service in Tuskegee, Alabama, deliberately withheld the drug from infected African-American men—impoverished and mostly illiterate—without their consent, so that they could study the full progression of the disease.
These experiments happened to be the subject of Jonah Goldberg's May 2, 2008 column, Tall Tales About Tuskegee. The Tuskegee study began in 1932. Much later, when penicillin treatment for syphilis was developed, it does not appear to have been clear it would be appropriate for the study participants' advanced cases. The problem with Tuskegee, from today's perspective, was
They were told they were getting “treatments” when they were merely being studied.
That's not particularly pertinent to the issue of embryonic stem cell research.