***So why did European attitudes toward the Indian, initially so favorable, subsequently change? ***
One word. BRUTALITY.
Consider this term. Sel-vedge. It means "dwellers of the green forest." This is what all natives everywhere were called at that time.
The term was corrupted to "salvage" and then "savage" and today is a euphamism for intense brutality. "Savage fighting. Intense Savagry. Uncivilized form of warfare," ect.
The Spanish were the first to find Indians scalping Indians. Later it was reported by the French and English explorers years before they were supposed to have taught the Indians to do so.
I like the discription of scalping as seen by Captain John Smith..."They cased off the hair with knives made of shell and reeds and hung them on a rope streached between two poles"
The beautiful engravings of Theodore de Bry shows several scalps, arms and legs also hung in such a manner.
European colonists still considered the Indian to be a noble savage that could be educated into honorary whites. Of course, it depended on which tribes they ran into. Not every tribe of indigenous people were bloody. I was just reading that fact today in Dinesh D'Souza's book What's So Great About America? That's a really good book, and End to Racism is his finest.
One word. BRUTALITY.
Wrong word. The word should be "Greed".