As surprising as this may be to some people, there is no debate within the medical community as to when life begins. Life begins at conception. Therefore, every "succesful" abortion ends the life of a living human being, and we're not asking you to take our word for it. Consider the testimony below from an assortment of leading embryology textbooks.
The Developing Human: Clinically Oriented Embryology, 6th ed.
Keith L. Moore, Ph.D. & T.V.N. Persaud, Md., (Philadelphia: W.B. Saunders Company, 1998), 2-18.
"[The Zygote] results from the union of an oocyte and a sperm. A zygote is the beginning of a new human being. Human development begins at fertilization, the process during which a male gamete or sperm ... unites with a female gamete or oocyte ... to form a single cell called a zygote. This highly specialized, totipotent cell marks the beginning of each of us as a unique individual."
Essentials of Human Embryology
William J. Larsen, (New York: Churchill Livingstone, 1998), 1-17.
"In this text, we begin our description of the developing human with the formation and differentiation of the male and female sex cells or gametes, which will unite at fertilization to initiate the embryonic development of a new individual. ... Fertilization takes place in the oviduct ... resulting in the formation of a zygote containing a single diploid nucleus. Embryonic development is considered to begin at this point... This moment of zygote formation may be taken as the beginning or zero time point of embryonic development."
Human Embryology & Teratology
Ronan R. O'Rahilly, Fabiola Muller, (New York: Wiley-Liss, 1996), 5-55.
"Fertilization is an important landmark because, under ordinary circumstances, a new, genetically distinct human organism is thereby formed... Fertilization is the procession of events that begins when a spermatozoon makes contact with a secondary oocyte or its investments... The zygote ... is a unicellular embryo... "The ill-defined and inaccurate term pre-embryo, which includes the embryonic disc, is said either to end with the appearance of the primitive streak or ... to include neurulation. The term is not used in this book."
Adding to the consensus of contemporary textbooks, is the testimony of older medical texts as well:
Human Embryology, 3rd ed.
Bradley M. Patten, (New York: McGraw Hill, 1968), 43.
"It is the penetration of the ovum by a spermatozoan and resultant mingling of the nuclear material each brings to the union that constitues the culmination of the process of fertilization and marks the initiation of the life of a new individual."
Biological Principles and Modern Practice of Obstetrics
J.P. Greenhill and E.A. Friedman, (Philadelphia: W.B. Sanders, 1974), 17.
"The zygote thus formed represents the beginning of a new life."
Pathology of the Fetus and the Infant, 3d ed.
E.L. Potter and J.M. Craig, (Chicago: Year Book Medical Publishers, 1975), vii.
"Every time a sperm cell and ovum unite a new being is created which is alive and will continue to live unless its death is brought about by some specific condition."
In addition to the consistent testimony found in medical textbooks, there is some equally conclusive evidence that exists on the public record. In 1981, a United States Senate judiciary subcommittee received the following testimony from a collection of medical experts (Subcommittee on Separation of Powers to Senate Judiciary Committee S-158, Report, 97th Congress, 1st Session, 1981):
Professor Micheline Matthews-Roth
Harvard University Medical School
"It is incorrect to say that biological data cannot be decisive...It is scientifically correct to say that an individual human life begins at conception."
Dr. Alfred M. Bongioanni
Professor of Pediatrics and Obstetrics, University of Pennsylvania
"I have learned from my earliest medical education that human life begins at the time of conception."
Dr. Jerome LeJeune
Professor of Genetics, University of Descartes
"After fertilization has taken place a new human being has come into being. [It] is no longer a matter of taste or opinion...it is plain experimental evidence. Each individual has a very neat beginning, at conception."
Professor Hymie Gordon
"By all the criteria of modern molecular biology, life is present from the moment of conception."
Dr. Watson A. Bowes
University of Colorado Medical School
"The beginning of a single human life is from a biological point of view a simple and straightforward matter the beginning is conception."
The official Senate report reached this conclusion:
Physicians, biologists, and other scientists agree that conception marks the beginning of the life of a human being - a being that is alive and is a member of the human species. There is overwhelming agreement on this point in countless medical, biological, and scientific writings.
This, of course, should come as no surprise since the American Medical Association (AMA) declared as far back as 1857 (referenced in the Roe. v. Wade opinion) that "the independent and actual existence of the child before birth, as a living being" is a matter of objective science. They deplored the "popular ignorance...that the foetus is not alive till after the period of quickening." Doctors knew it during the 1800's and doctors know it today. Human life begins at conception.