[mig39]

In the article he finds the first written mention of the "purpose" of the spiral going in one direction is in 1902. And explains that this 1902 author was obsessed with spirals and fencing.

I think the fact that there are no primary historical source documents that say "hey, we're building this castle this way just in case it's breached and we have to have a sword fight on the stairs" is one of his main points.

It would be easy to disprove the article author by finding such historical documents. Do they exist?