In “Abortion: beyond polarized views” (Aug. 5), Martin Shupack states that “neither Scripture nor science can prove abortion is homicide.” However, a combination of science and logic, under guidelines for ethical thought, may guide us.

Consider that a comatose person on life support can neither think nor communicate and depends on machines and other humans to survive. We can measure brain and other bodily functions and predict whether this mass of cells will regain the functions of a sentient human. If there is a reasonable expectation of this, they are afforded all the support necessary to sustain life. Only if there is no reasonable probability are they no longer considered a person, and artificial life support can be withdrawn.

Now consider a conceptus or fetus — also a mass of cells that cannot provide for itself, depends on nourishment through the placenta and cannot respond cognitively. It is in an almost identical situation as the person on life support, though we cannot measure brain function. However, it has a high probability of gaining all the attributes of a person and therefore also should be afforded all the support necessary to sustain life.

The validity of ethics is proportional to their consistency: The greater the con­sistency, the greater the validity. Since a comatose person and a conceptus/fetus are in apparently identical circumstances, the definition of life and death needs to be the same. Biology, logic and ethics indicate a conceptus/fetus is a human being at conception, in the same way that a comatose person on life support is human. What we do with this information is a matter for further discussion, but always with the knowledge that abortion at any stage takes a human life.

David L. Weldy, Monclova, Ohio