At the heart of the pro-life debate is the ultimate question of when life begins. In recent years many different people and organizations have attempted the change the definition of when life begins from conception to other points like implantation, viability, heartbeat, and even the ability to reason. Oftentimes people in the prolife movement argue against these claims with the use of religion or science. While there is certainly room for scientific and theological arguments for the beginning of life often the most effective argument is the basic argument from reason.
While modern advances in medicine make it clear that life begins at the moment of conception, the moment of fertilization when two gametes join to form a new organism, a strong claim for the beginning of life can be made apart from science with the use of reason. Any human person with a basic ability to reason should be able to understand that human life begins at conception. Simply put it is impossible for a thinking person to hold that life begins at any point other than conception.
Any rational person will agree that an embryo, left alone in a mother’s womb, will grow to maturity as a human person. An embryo is not simply a group of cells that may or may not develop into a crying baby. The embryo is not just a useless glob of tissue that will amount to nothing, but rather a person who will develop into crying human baby. In other words the embryo, left alone under the usual conditions, will develop into a child that will be recognized by everyone is already a human being.
It is in fact the moment of fertilization and not some other moment like implantation that is the most significant stage in the life of a new human person. It is at the moment of fertilization that the new human person acquires a unique and irrevocable identity. While it is certainly true that that person may never be able to develop or even arrive at a point of implantation in the mother’s womb, as in the case of an ectopic pregnancy, that new organism exists from the moment of fertilization and thus has an identity.
From the moment of fertilization an embryo has the ability to grow into what everyone will acknowledge to be a human person. The embryo, from the moment of fertilization, is a human embryo; it will only become a human person and not a monkey or even an oak tree. From the moment of fertilization the embryo is a being because it is whole being, that is it contains within itself all that it will need to develop into a mature child, with an existence. The embryo, while not looking like a human person, certainly exists and lacks nothing. Those who argue that an embryo does not look like a child and thus is not a child miss the point. An embryo does look like a child at birth; it looks like a child at that particular stage of development just as a new born baby does not look like he will look when he turns 80.
Recognizing a human person exists from the moment of conception is as simple as stopping for a second to think through the claim. Simply, put from the moment of conception a child has a unique identity and given the proper conditions will continue to develop into what we consider to be a child. If only people would stop for a moment to think clearly about when life begins their eyes would be opened to see the horror of abortion as murder.