Before the 19th century, the English language contained room for some very idiosyncratic notions about capitalization. People just threw them in wherever and whenever they wanted. For instance, here’s the first paragraph of Hobbes’ Leviathan (as taken from the electronic version of a 1651 version of the book).
Concerning the Thoughts of man, I will consider them first Singly, and afterwards in Trayne, or dependance upon one another. Singly, they are every one a Representation or Apparence, of some quality, or other Accident of a body without us; which is commonly called an Object. Which Object worketh on the Eyes, Eares, and other parts of mans body; and by diversity of working, produceth diversity of Apparences.
This drives me insane! Oh god I hate it. I mean I can take the idiosyncratic spelling (although even that is annoying), but the capitalization makes the text unreadable.
However, what’s worse is that many modern editions of these texts will reproduce these usages! Why?!?!?!
I think there’s some sense that if you’re going to read an old text, then you’re obviously doing it for some sort of scholastic or educational purpose, in which case you’ll obviously want the author’s original capitalization. In America today, the study of early texts has been so taken over by the universities that publishers can’t fathom the idea that an ordinary person–a lawyer or an insurance broker or a factory foreperson–might want to read these texts for their own personal edification. And, because of that, all of these texts are produced in ways that best suit the needs of professors and students.
Lucky, the good people of the University of Adelaide, in Australia, have a distinctly different notion of what’s needed, and it is to them that I turn whenever I want to find a decent electronic edition of an older work.