Still, in both eras movement artists desired to have the authority of some all powerful "science" on their side; a desire which seems absurd now, in a time when no one is contesting my right or my duty to practice and teach gongfu. Politics is not a rational process. Lineages are a political tool, not a rational one, and certainly not scientific.
Perhaps I accidentally implied that no lineages are real. Shaman, Wu, Tangki, magicians, even puppeteers pick disciples to whom they give the responsibility of passing on a classical art or ritual tradition. In India, Japan and China the disciple is often a family member, but if the extended family hasn't produced any suitable offspring, a disciple will be adopted.
The more illegal (remember legal/illegal is a continum in China) an art is, the more likely it is to be secretive. Also, magicians, martial arts and ritual experts usually had good reasons to keep trade secrets close to their chests. Lineages served this political purpose well. The early 20th century ridiculed secretive behavior none the less, and people at least pretended that all their secrets had been revealed. (I believe Cheng Man Ch'ing wrote a book on Tai Chi book called, "There Are No Secrets.")
I don't believe there are real historical martial arts lineages which were devoid of performance, ritual, religion, or rebellion. But lineage, by its nature, is a changing thing and could certainly purge itself of these aspects and remain a lineage. But be suspicious, a martial art that has had a lot of purging will also have a lot of inexplicable baggage. It's a lot easier to assess the value of an art when you have the whole thing intact, and NOBODY seems to have that!
I suspect there was some previous era where martial arts were shared freely. Buddhist temples had open courtyards where locals could get together and practice. Villages had clan halls where people could get together and practice. I think there was always some paranoia, but it may have been more like basketball secrets. Every village and every temple sponsored a team, and everyone wanted the quality of their competing teams to be high--so after dominating for a few seasons-- you traded coaches.
I'm optimistic that the commercial world is leading us into an era of great sharing.
If there was a "how to" martial arts literature prior to the Ching Dynasty, it seems lost to us now. Martial arts have come down to us primarily as the arts of the illiterate. I do believe at one time martial arts were "high-culture." The evidence for that is in the philosophical literature of the Waring States Era. It is entirely possible that the Tang and Song Era had these too, but perhaps they were destroyed during the years of Mongol rule.
The other group of people who have lineages are Daoist Priests, Daoshi. Daoism is a lineage tradition, everyone given the title Daoshi was included in a lineage and each individual teaching or text had its own lineage. In the event that someone set off on their own and created some new supportive practice or teaching, after a generation or so it/they would be incorporated/adopted into existing lineages. Scholars have their doubts about just how far back some of these lineages go, but no one doubts that they do go way back. But it is also true that most of these lineages are secret. The ones we know about are the ones that stopped being secret to some extent. I suspect that martial artists, beginning in the Ching Dynasty, started imitating Daoist (and Buddhist) ideas of lineages. Martial arts may not have had lineages before that.
Then again their may have been secret Daoist lineages of martial arts. As Shahar points out in his book Shaolin Temple, the popular literature of the Yuan and Ming Dynasties grew out of theater and is perpetually making fun of Daoists, Buddhist, officials, and martial heroes (xia) with their secret techniques.
I've been looking through the index to the Ming Dynasty Daoist Cannon (Daozang) which was just published last year. There are a lot of texts which describe physical practices in conjunction with ritual, purification, astrology, meditation etc... There may even be a few texts which are primarily movement oriented (requiring lineage transmission, of course), but I see nothing resembling martial arts. If such texts ever existed they are either still hidden, or they were destroyed 900 years ago a long with thousands of other texts during the Yuan Dynasty.