The psychological study of concept formation reveals that human perception of basic categories is not based upon detection of distinct boundaries, but rather upon an intuitive sensing of central tendency and clustering. It thus becomes clear that the historical effort to establish the reality of basic categories by determining precise boundaries is irrelevant and misdirected. The witness of the most relevant area of scientific, psychological investigation corroborates Scripture and naive conviction to the effect that there are real and distinct identities and categories. God's created categories are clearly seen, not only through Scripture revelation, but in the creation as well. He has shown them to us, and they are manifest in us.
Man is without excuse.
The faces of Adam and Eve, or Noah as genetic prototypes may be distinctly and strangely familiar to us. And then, of course, there is that face. It is beyond the scope of this paper, but it should be pointed out that there is still no repentance. Instead, 20th-century man is turning increasingly to the ultimate delusion of shamanistic sorcery and occult mind power in an attempt to create whatever categories are desired. The accompanying bibliography contains a listing of research studies of the type discussed in this paper.