Whether the Earth was created in 7 days, or 7 actual eras, I'm not sure we'll ever be able to answer that.
Beyond the sheer graphic impact of so much disease, distortion and disfigurement, what distinguishes them is an acute paradox: here the styles and modes of bygone eras are used not to prettify people or create a picturesque landscape, but to render the pathological as clearly as possible with a view to instructing physicians.
Even petrol prices are – if we think of how long we have to work to earn enough to fill up a tank in comparison with previous eras of high petrol prices.
So, in the midst of all this, are we living in a particularly dark age for parenting, or one of the sunnier eras on record?
As he has flipped back through back issues of the NME from his time on the paper, he says he has been struck by how brief eras like punk, post punk and 2 Tone were.
"Maybe it's sentimental of us, but we hold fast to memories and moments, to relics from bygone eras.
Butterflies have been considered to be human souls in many eras and cultures: in 17th-century Ireland, an edict forbade the killing of white butterflies because they were regarded as the souls of children.
"Different eras of music are so much a response to what's going on at the time, and country has a bit of warmth about it.
He apparently added that production was nearly complete, and he was very happy with the result; Moffat is of course well versed in hopping between eras, having written numerous episodes of Doctor Who.
Mr Summers had what in previous eras would be the two most important qualifications to lead the central bank: unimpeachable economic credentials and the trust of the president.
These responses distort the functioning of the economy, often reducing potential growth and the economy's ability to provide a high standard of living to all.The supply-side tax revolutions of earlier eras prompted a wave of studies looking at the effect of lower taxes.
