Long dashes between sentences

In Ludwig Wittgenstein's writings, I often see long dashes (both em-dash, and one even longer, shown in red circles). I can sense (at least I believe I do—perhaps, from the writer's point of view, the two thoughts are tightly-connected, yet they have to be separate sentences) their function; but is there such a usage? Never seen any punctuation guide mentioning such a usage.

Understand that not too long ago everyone wrote stuff out in longhand. Certainly no computers, and, even if they existed, typewriters were reserved for use by secretaries and typists.

In longhand it's easy to develop a (personal) style (perhaps varying from one document to the next, or even within a document) where you use dashes of varying length to set aside parenthetical text, emphasize certain phrases, separate lines in a poem, indicate an elision, etc. Since the length of the dash is purely a matter of how far the pen moves on the paper, there is no motivation to standardize this, other than what ones headmaster may pound into ones head in school.

And pity the poor typesetter who must read the longhand scrawl and attempt to interpret its meaning. Typesetters would attempt to understand the intent of the markings and "standardize" it to some extent, but they could only do so much, especially when the author was fond of long, convoluted sentences.

So you are left to attempt to understand the markings yourself, perhaps based on "standard" usage, or perhaps throwing that out the window and developing a new interpretation.