I many times heard a version that the advances of the Ancient Greek culture were in fact borrowed from Egypt or the Middle East. I will not buy this. Classical Antiquity civilization had a lot of features which put it apart from any Asian or African civilization and which thus could not be borrowed. Such features include
extensive and realistic fine arts, especially sculpture
narrative literature of non-religious character
philosophical research based on logic, experiment and cross-references between authors
extensive deductive legal system and idea of the people as the source of power, idea of counter-balances and checks on the supreme power
Another idea, that these features were inherited from Proto-Indo-Europeans does not explain why other IE peoples did not exhibit similar culture.
It seems that proto-Classic civilization originated in the Balkans and encompassed several diverse peoples of IE origin (Proto-Greeks, Thracians (including Dacians), Illirians, Macedonians, Liburgians, Messapians, Paeonians, Bryges (later known as Phrygians), possibly also proto-Italians).
So my question is
What are the arguments pro and contra of proto-Classical civilization in the Balkans?
Are there any remains that point that such civilization existed?
Whether there are other theories of the origins of the Classical culture?
If proto-Classical culture existed, whether it played any prominent role in Europe such as playing a role of a cultural center?