The euphemism “the natural law, which is inscribed unto every human heart” is sheer nonsense. What it implies is that humans are born with a “natural set of do’s and don’t’s”, or a “natural moral guide”. Of course biology has proven that humans are born “tabula rasa”, a clean slate. Our brain is not “preformatted” like the neural system of insects. It is our greatest strength that we are able to learn. We do have an affinity to learn languages, and via the languages we learn everything else.
There are a couple of dozen of “feral children”. These poor beings grew up in a wild environment, without human companionship. As such, during their formative years they were not exposed to languages, and so they never learned to communicate. They are unable to learn to speak. They are essentially wild animals in a human form.
So to keep talking about some “pre-wired” morality (which these children clearly lack) is a biological absurdity. Our moral norms are a learned behavior. It is one thing to keep on believing all sorts of “angels” and “demons” - after all these alleged beings cannot be detected, and as such cannot be proven or disproven. It is a completely different ballgame to believe what has been shown to be false - like this ridiculous concept of “natural law - inscribed unto the human heart”. To keep on believing nonsense like this marks the believer as a fully irrational person. It is a sad thing that so many of the posters around here keep on believing these and other assorted nonsense, and when they are told about their error, they simply close their ears.
I’ll mostly just address the biological end of this argument, since you deny teleological responses.
When you say things like “Of course biology has proven that humans are born “tabula rasa”, a clean slate,” you are displaying a fundamental ignorance of science and biology on multiple levels, as well as the nature of the scientific method. “Biology” doesn’t prove anything, individual scientists do research that can provide evidence one way or another, and most of those would disagree with your statement. You’re charting an interesting new course here, though, in breaking away from your atheist peers in stating that we are born
tabula rasa, BTW. Most atheists would disagree with you very strongly, as many of their arguments for a non-religious morality rest on an “evolved” or “inherent” sense of right and wrong, and base their arguments on inherited behavior using the theories of sociobiology and evolutionary psychology, and many biologists, psychologists, and anthropologists would disagree with you on the inheritability of behavior. But props to you for disagreeing with Richard Dawkins, Sam Harris, Edward Wilson, Charles Darwin, Konrad Lorenz, Leda Cosmides, John Tooby, Nikolas Tiinbergen, Lionel Tiger, Robin Fox (the last two are sociobiologists, not Beatrix Potter characters, BTW), Frans de Waal, Robert Wright, Donald Symons, Anne Campbell, et al! You can start your
own school of biology! You go, Spock!
Certainly it would be hard to argue that much human elective behavior (that doesn’t appear to be autonomic) is inherited, from a biological perspective - dogs that point aren’t taught to point, it’s inherited behavior within their species or breed. So your tabula rasa argument isn’t really supported.
The argument that feral children somehow represent mankind in its natural state can only be described as specious. Abandoned children are by definition abused, and don’t represent our true natures any more than a child born without full brain function does. As we are communal, family-based organisms, we require others to shelter, feed, and teach us from the earliest age, to deny these rights to a child is to handicap the child. The child is still human, and still has moral capacity, but obviously has a diminished sphere of responsibility from a moral sense, and would presumably be judged accordingly in a court of law or in divine judgment. If an individual’s cognitive faculties are not allowed to fully develop or function in the manner for which they are designed, that does not mean there is not an intended design. I can operate my car without properly lubricating it and the engine will not function; that does not mean that there is not a “correct” way for it to function, as intended by the designer of the vehicle.
As Alvin Plantinga wrote,
Many systems of your body, obviously, are designed to work in a certain kind of environment. You can’t breathe under water; your muscles atrophy in zero gravity; you can’t get enough oxygen at the top of Mount Everest. Clearly, the same goes for your cognitive faculties; they too will achieve their purpose only if functioning in an environment much like the one for which they were designed.
We can say that a feral child’s cognitive faculties are stunted because they are not used in the way for which we, as humans, are designed - to learn from our human parents and those around us.
Plantinga further noted that the notion of proper function for any system is inextricably bound to the notion of a design plan - our bodies are constructed in such a way, that there is a way that they
should work and are
supposed to work, which requires a
design in our cognitive faculties, as well as a designer. The fact that, due to abuse or malfunction, one’s cognitive functions don’t easily recognize the Natural Law, does not invalidate the concept of Natural Law.