On the use of "Ad" + section number in a work of German philosophy from the early 1700's

Question

I am trying to get familiar with a work by German philosopher Christian Wolff. The book is called Vernünftige Gedanken von Gott, der Welt und der Seele des Menschen, auch allen Dingen überhaupt. I have a PDF copy of the third edition, from 1733.

The work is divided into 426 sections. At the end of many sections, though, there is a line like this:

Ad §. 169.

At first I thought that these were references to other sections within this same work, but it doesn't seem like that can be right, since some of the references are to section numbers that fall beyond the 426 listed in the book. The "Ad." may be a Latin abbreviation, as there are some Latin words in the text (the majority is the old German script).

Below I have included two screenshots of what I'm talking about. Does anyone know what these references mean in general (and what they could mean for Wolff in particular)? Many thanks.

Answer 1

Als Nichtlateiner kenne ich nur ganz wenige, lateinische Phrasen, etwa "ad hominem" und darin ist das "ad" keine Abkürzung, wie auch der Screenshot 2 Verwendungen ohne Punkt zeigt, wärend ansonsten an Punkten nicht gespart wird.

In "ad hominem" heißt "ad" soviel wie "zu" (zur Person), und also wird das Ad für Zu stehen, also "Zu Paragraph 18.20" im Zusammenhang.

Answer 2

Latin ad (or German zu, zu[m] Punkt) is used similar to re (bezüglich = bzgl., in Sachen / in der Sache/Angelegenheit) – as popularized by email subject lines – in sophisticated German. The former is most often used with numbered items as in enumerated or ordered lists, but sections or paragraphs in this case, the latter more with spelled out topics, and re is even less common than ad in contemporary German.

In recent texts, I’ve only seen ad being used by older professors of philosophy or linguistics and by people who wish they were one – they also tend to write stuff like qua for durch or per.

You seem to have basically figured out the answer yourself prior to asking, the problem was just that the frame of context, which should have been established in a foreword or introduction, was unavailable to you.