I guess the consensus is this is a pretty vague question. For the sake of throwing something out there, I suppose there is a some controversy about the exact quality and quantity of information that could be stored in the Inca recording system of knotted string known as quipus/khipus. There are very few surviving examples for us to actually examine, unfortunately. That said, I do not believe there is any debate that they can store numbers, as a simple base-ten numerical system is known to survive in some parts of Peru even to this day. Is that all that all that was ever stored in them?

There are a number of primary sources dating to within a generation of the fall of the Inca that agree the Inca bureaucracy was able to track things like census data, labour quotas, land allotments, work done, and all manner and quantity of stored goods in warehouses all over the empire. The common throwaway line is that not a single pair of sandals in an empire of twelve million taxpayers was ever unaccounted for. Was all that running off just the ability to tie zero through nine on a string?

To go beyond the Spanish chroniclers, there are colonial court records during the sixteenth and seventeen centuries where quipus were accepted as official documents by Spanish judges to settle property disputes. There is even a book dating to the time of Shakespeare --the Historia et Rudimentia Linguae Pruanorum, discovered in Naples, Italy in 1996-- that speaks in simple terms about a phonetic system of knots: Knots that record sounds instead of just numbers. As you can imagine, no one takes that idea lightly, but if it were true, the Inca had at least some kind of alphabet based in string that is entirely lost to us.

I am not saying that is likely, but we certainly do not have enough surviving quipus --or know enough about the ones we have-- to say categorically that it is impossible. Imagine if in the days before computers all the paper documents in the world that we could find were burned or buried or allowed to rot, and four hundred years later all that was left to find were a couple of old and incomplete ledgers, the print out from an adding machine, and a multiple choice scantron card where no one filled in any blanks. Would you want to be the historian who said all that pointed towards a lost alphabet?

It is a fun debate, but it is not one likely to be categorically won by anyone. I would call that a controversial theme.

Hello! My apologies if this seems obvious to you, but what do you mean by "controversial themes?" Are you referring to things on which there is no general academic consensus, or to topics some might consider "touchy?"

I'll echo CommodoreCoCo that this is a very open-ended question. Do you have any questions about specific things?

I'm referring to topics that people might consider "touchy" and controversial theme which there doesn't exist general academic consensus, about. Does somebody know ?

The information we have from the Inca Empire today comes from spanish people, so it far to say it's not 100 % reliable?