the relationship between ideas and time (four things to keep in mind)
1. All new ideas are not good ideas. The quality or value of any new idea at any given time is arbitrary. Value comes mostly (though not exclusively) with longevity, as the idea is enacted over time and is actualised, causing an effect. This effect can be bad. The effect does not follow any laws of causality or necessity; that is to say: something can be predicted to have an effect by a law of science or ethics or other rational or irrational set of rules, and still have any other effect. The rule-sets' worth are proven by consistency over time, not by being right every time. The invasion of Iraq may still (somehow) end up being a good thing (though obviously in my system of ethics is a bad thing until proven otherwise), while being kind to animals or clean can get you allergies or the plague.
2. Old ideas are not always bad ideas. There is no necessary progression towards any historical absolute singularity (though one could possibly occur). If things are getting better, they are not getting better by necessity. Mankind took a beating in the year 400, and life got very much shittier than it had been, and stayed that way for about a thousand years. Also, note that some of the old Greeks and Romans were on to something, and many of them were not. We can learn from 5500 years of recorded history. We can learn something from ancient Chinese poets, renaissance philosophers and the morning paper.
3. New ideas are not necessarily bad. Just as we are not necessarily moving with historical necessity towards some null point of joy, happiness, knowledge and oneness with the divine, we are not slouching towards some dystopic Bladerunnery hellhole. The fact that we have less time for each other and that we spend less time with our families etc. might be a problem with the present, but will not necessarily be a problem with the future. This does not mean that modern technology or the current culture is inherently sick. (Actually, the culture is sick, but not because it's new, and besides, we can fix that.)
4. All old ideas are not necessarily good. Dude, I don't care if the ancient Iraqis could build a battery, that doesn't mean they were sitting on the key to the spiritual truth about the universe. The yogic mystics were mostly off their heads, the ancient aztecs sacrificed humans to (presumably) immaterial, (presumably) non-existant beings, John the Babtist was probably high on magic mushrooms and Jesus, while quite the visionary, was not a little bonkers.
Plato was completely wrong: there are no absolutes in the world of ideas. You just have to start the clock to find out.
Speaking of number 2:
What historians know of the Harappan civilisation makes them unique. Their society did not like great differences between social classes or the display of wealth by rulers. They did not leave behind large monuments or rich graves.
They appear to be a peaceful people who displayed their art in smaller works of stone.
Their society seems to have petered out. Around 1900 BC Harappa and other urban centres started to decline as people left them to move east to what is now India and the Ganges.
This discovery will add to the debate about the origins of the written word.
It probably suggests that writing developed independently in at least three places - Egypt, Mesopotamia and Harappa between 3500 BC and 3100 BC.