Re:-If you were a south american indian running butt naked through the jungle, would you be happy being ignorant and quaint, and then die at thirty-five, or would you like the opportunity to be not-so-quaint and live to be a hundred?
Or...would you like to live at the capricious mercy of an government authority without any regress to fairness or justice?

Well Milo, dearest, lets compare apples to apples..

300-400 years ago, when European civilization met the civilization of south america, they had--an elaborate calendar (inca, aztec and mayan) writing, (mayan) well developed cities with central governments, and monumental architecture. The many system had all land owned by central government..(which was a religious ruler, but since all european kings/queens were "anointed by god" it wasn't all that different.

everybody had to work the land (in reality, "lord" and "bishops" only did a small amount of ritualized work) 1/3 of the crop went to worker, one third to local lord, and 1/3 to "god king" (church) -- doesn't sound great, but lets compare that to serf or indentured workers in europe... fact is, most of the european explorers commented on how healthy and well fed the local populace was..

The biggest gains in life expectantly come from not drugs, or labor saving devises, but from access to clean water. in this respect, western europe really didn't make great strides till mid 1800... Remember Prince Albert died of typhoid, a disease caused by drinking water contaminated by faeces. and there have been out breaks of typhoid is the past 25 years in europe, (ireland, scotland, italy all come to mind) (yes, in south america too, but typhus was an introduced disease, not known before european settlement)

and as for running butt naked, while american native (both north and south american) lacked most domestic animals, they had domesticated some.. in south america the llama, alpaca and relatives provided a ready source of wool, (and meat) and in north america, the hopi's had semi domesticated sheep, (and were weaving before europeans arrived, with looms almost identical to looms used in classical roman times.) and the pacific northwest Indians had developed a breed of dog that was keep for the soft hairs on its underbelly, that were woven. Cotton was domesticate in both China and in the americas and hemp was also used for fiber, and pineaple fronds.

The america were settled later in time than europe, and lacked many of the nature resources that make europe so successful (there are almost no domesticated animals today that originate here in americas,(turkey, guinea pig, llama) but many, many more domesticated and cultivated plants. Maize, (corn) peanuts, potatoes, cocoa (chocolate), tomatoes, chilies (peppers) many hardy varieties of squash, many varieties of beans, pineapples, banana's, all come to mind.

many of these, are extremely nutritious. Potatoes, with just a small amount of milk and greens make a complete diet-- corn and beans also often complete nutritional package.. a diet of peanuts, corn, beans, potatoes, tomatoes, chilies, cocoa, and squash was available year round(ie, the food either keep well, or could be harvested in different seasons), cheap, and offered more variety and nutritious than the common fare of the poor farmers in europe; (grains,{wheat, barley, oats} and vegetables, dairy. (both cultures used fish too, as cheap source of animal protein.)

Corn brews up a nice beer, too, as do other plants, so liquid refreshment was not lacking.

many "staple" diets of europeans today are dependant on american imports. Hungarian paprika is "american" and offers a huge amount of vitamin C year round. "irish" potatoes" are american and saved (and starved) the irish.

as for governments.. again.. most of the gains have been made in the past 100 years -- past 50 in US for many minorities. i don't think the spanish inquisition was a big improvement in the live of most south american natives..