I don't want to be presumptuous here, but does everyone understand the "unspoken" portion of the subject line?
Unless I am wrong -- and please don't hesitate to smack me down if I am -- Craig is refering to the longstanding "Nature or Nurture" debate.
Are we all just products of our environment?
We can't be, as demonstrated by the multiplicity of genetic diseases. Here's a list of some of them from Yahoo:
Achondroplasia Achromatopsia Acid Maltase Deficiency Adrenoleukodystrophy
Aicardi syndrome Alpha-1 Antitrypsin Deficiency Androgen Insensitivity Syndrome
Apert Syndrome Arrhythmogenic Right Ventricular Dysplasia Ataxia Telangiectasia
Barth Syndrome Blue Rubber Bleb Nevus Syndrome Canavan Disease Cri Du Chat Syndrome
Cystic Fibrosis Dercum's Disease Ectodermal Dysplasia Fanconi Anemia Fibrodysplasia
Ossificans Progressiva Fragile X Syndrome Galactosemia Gaucher Disease
Hemochromatosis Hemophilia Huntington's Disease Hurler Syndrome Hypophosphatasia
Klinefelter Syndrome Krabbes Disease Langer-Giedion Syndrome Leukodystrophy
Long QT Syndrome Marfan Syndrome Moebius Syndrome Mucopolysaccharidosis (MPS)
Nail Patella Syndrome Nephrogenic Diabetes Insipidus Neurofibromatosis
Niemann-Pick Disease Osteogenesis Imperfecta Porphyria Prader-Willi Syndrome
Progeria Proteus Syndrome Retinoblastoma Rett Syndrome Rubinstein-Taybi Syndrome
Sanfilippo Syndrome Shwachman Syndrome Sickle Cell Disease
Smith-Magenis Syndrome Stickler Syndrome Tay-Sachs
Thrombocytopenia Absent Radius (TAR) Syndrome Treacher Collins Syndrome
Trisomy Tuberous Sclerosis Turner's Syndrome Urea Cycle Disorder
von Hippel-Lindau Disease Waardenburg Syndrome Williams Syndrome
Wilson's Disease
I'm not a doctor, and frankly I don't know what most of these diseases involve, but the important point is that NONE of them are a result of the environment (nurture); no one got the disease from a toilet seat or from drinking a potion; no one "signed up" for them, saying, in effect, "Yeah, give me some of that there Huntington's Disease - I want to go crazy before I reach the age of 40."
Now, if diseases - an obvious defect - can be inherited, isn't it reasonable to think that more subtle gradations of variance from THE IDEAL can occur as a result of genetics (nature)? Of course it is.
But there is hope!
Because man has a rational mind, he is able, given time, to understand the causes of even these genetic diseases. We are approaching (not in our lifetimes, perhaps, but not too far off) an age where inherited deficiencies can be treated and cured -- not by the action of some imaginary invisible Sky King in New Jerusalem 90210, by by the dedicated effort of workers in the fields of science and medicine.
Religionists would have you believe that these people are inherently "sinful," "imperfect," and inclined toward Satanic services of all sorts, yet our only real hope for a better future is with these workers in science and medicine, not with some imaginary sock puppet.