Although the potential applications of human embryonic stem cells and therapeutic cloning hold promise for the alleged medical benefits, these technologies have posed profound ethical issues because they necessitate the destruction of human embryos. A fundamental point in the issues is the concept of the moral status of human embryos. The Catholic Church has held that human life begins at the moment of conception and therefore, has defended the dignity, inviolable right to life and integrity of human embryos. The Catholic Church has opposed human embryonic stem cell research and any kind of human cloning because they are contrary to the dignity of procreation, of conjugal union and of human embryos. Moreover, these techniques have the risk of creating a sub-category of human beings that are destined basically for the convenience of others. In conclusion, science and technology can never be independent of the criterion of morality, since technology exists for man and must respect his finality.