I was curious to know if midpoints are a modern invention or do they derive from classical sources? Also, can anyone list the earliest written sources about midpoints.

The first delineations of midpoints per se, to my knowledge, are in Alfred Witte's Rules for Planetary Pictures first published in 1928 in German. This text can still be found in English. The work usually associated with midpoints in our own time is Reinhold Ebertin's The Combination of Stellar Influences (1940) From what I can tell, this is a revision of Witte's work.

In the introduction to this work Ebertin tells us:

The use of half sums (i.e.midpoints - tc) is not new, as can be seen from the rectification used by Guido Bonatti (apparently born the year 1230 at Casica near Florence) who was the famous Court-Astrologer of the Emperor Federick II. Furthermore Alan Leo, the well known English Astrologer and founder of "Modern Astrology," a journal now edited by Charles E.O. Carter in London, speaks of the mid-point between two planets which is touched as it were by the passage of a directed stellar body.

Another astrologer, Frank Glahn, writes that he got his first knowledge of he "intersecting points" from Albert Kniepf, a particularly gifted astrologer, whose writings had appeared at about 1900 in Hamburg. Alfred Witte, the founder of the Hamburg School of Astrology, had also been informed by Kniepf about the application of this method according to Glahn, and it is to Witte's credit that he has introduced the pattern working method to modern astrological practice coining the name "planetary pictures."

[The Combination of Stellar Influences, AFA 1972, page 21]

What is interesting is the "hit and run" treatment of Bonatti (what rectification? where?) without so much as a hint as to what he did or where it can be found. The reference to "Frank Glahn," on the other hand, gets a footnote citing the work.

Some astrologers have made mention of a connection between the Arabic Parts and midpoints, claiming, as all good Darwinists do, "evolution," but I've never been able to resolve that connection. They are both derived mathematically (so is antiscion), but the parts have a dispositor who pays a role in the delineation, whereas the midpoints are just that: "points" that become activated when contacted either by conjunction or aspect. In this respect they more closely resemble antiscion. So they're calculated a little bit like the lots and used a little bit like antiscion.

I would be surprised if the inventor(s) of midpoints looked at Bonatti and said, "Oh look, here's an idea!" My guess is that he was tossed in by Ebertin in order to maintain some sense of historical continuity.

Tom

I cannot comment on Bonatti but I do remember that Olivia Barclay in her book Horary Astrology Rediscovered quotes at least one example of what she considers midpoint use by William Lilly in Christian Astrology.
Indeed, Barclay's enthusiasm for midpoints is one of things that most surprised me when I was reading the book. I thought it all stemmed from Uranian Astrology and Cosmo-Biology as Tom states above. In practical terms it did since whether it existed or not in the tradition it was only the influence of Witte and Ebertin that brought Midpoints use into prominence.

I don't have Barclay's book to hand right now. I will post the details later.

Mark

I was a bit surprised to learn this and ran to my copy of Horary Astrology Rediscovered. I looked up "midpoints" in the index and found recommendations for their use, but nothing on Lilly. Then on page 309 I found this:

[There is only one instance where Lilly almost used a midpoint: the Moon's sextile fell at a degree midpoint a Sun/Mercury opposition, and saved the ship]

She gives no reference, which means someone will have to check out ships in CA, although the above sounds like a translation of light. I'll get back to this later today.

Tom

I was just thinking in Olivia Barklay ! In an article in http://www.qhdc.org/barclay/exeter.htm go all the way down, is almost the last paragraphe, she says:

For general use, I recommend Lee Lehman's 'Book of Rulerships', published by Whitford Press. And none of us can omit 'The Combination of Stellar Influences'. Did you know Firmicus mentions midpoints in the fourth century?

Yuzuru

From Wikipedia:

A midpoint is a mathematical point halfway between two stellar bodies that tells an interpretative picture for the individual. There are two types of midpoints: direct and indirect. A direct midpoint occurs when a stellar body makes an aspect to the midpoint of two other stellar bodies with an actual physical body at the halfway point. In other words, a direct midpoint means that there is actually a stellar body in the natal chart lying in the midpoint of two other stellar bodies. An indirect midpoint occurs when a stellar body makes an aspect to the midpoint of two other stellar bodies without a physical body at this midpoint.[1]

Midpoints were first used as Half-Sums by Ptolemy in the 2nd century, with the concepts of the 1st and 2nd harmonics. Midpoints were known and used to calculate Arabian Lots or Parts, like part of fortune in the 3rd century. Guido Bonati used direct midpoints (1123–1300) in the 13th century to refine timings in an event chart. Alfred Witte was the first person to do a lot of investigation on midpoints using movable dials and together with Ludwig Rudolph and Herman Lefeldt formed the Hamburg School of Astrology and the technique with the use of Trans Neptunian points was called the Uranian Astrology.[2] Then, Reinhold Ebertin in his book Combination of Stellar influences[3] included psychological principles and simplified the midpoint technique, removing the Trans Neptunians used by the Hamburg School. These were further popularized by American authors Aren Ober (formerly Savalan) and Eleanor Kimmel.

https://en.wikipedia.org/wiki/Midpoint_(astrology)

In a lecture at the 5th International Conference of the IUF in New York in October 2010, Michael Feist gave an overview of the early years of The Hamburg School.

The astrologer Friedrich Sieggrun founded with his students in spring 1915 the study group "Kepler-Circle." which puts mathematics, science and astronomy (Uranus) into the foreground of the astrological view. Ludwig Rudolph was the youngest member and secretary of the Kepler-Circle. In 1919, after the First World War, they invited Alfred Witte.

Note: The name of the study group in itself reveals the influence or interest of The Hamburg School.

As for the name, the 'Hamburg School' was taken up fast.
The American Richard Svehla, Phoenix Bookshop, Cleveland, Ohio, was in the early 1930's one of the first who introduced the Witte-Astrology in the USA. After initial contacts Richard Svehla suggested to Ludwig Rudolph to form a team, in 1933 and he received an exclusive authorization for selling books and tools of the Witte publishing house. And the Hamburg School in the USA inspired Svehla for the name 'Uranian System of Astrology', formed from the first letters U.S.A.

Reinhold Ebertin with 'The combination of Stellar Influences' removed the Uranian planets and gave a more sophisticated approach to the midpoints centered on psychological and health aspects.

Although it was never called a midpoint system, the Parts in astrology have the same approach A+B-C. And they go very far in time.
By itself, it is not a planetary picture but if you find a 3rd planet in A+B-C= X you can start to build some understanding on how midpoints work.

Gary Christen gives this example with the Part of Fortune



'Essentially, we are looking at the midpoint of the Asc and Moon. (Note: or the midpoint of Sun and Fortuna). Taking the distance from the midpoint to the Sun and adding it to the opposite side of the midpoint axis gives us the position of the Part of Fortune. This point can be occupied by a natal, progressed or transiting factor, or can be occupied by elements of another horoscope, or it can be completely unoccupied. If it is occupied, then the meaning of the Part of Fortune will become expressed through the particular factor that occupies it. If the Part of Fortune is unoccupied, it remains a sensitive point that can fall in a house and sign whose meaning is significant for the native.'

Hi Ouranos

Shall we play a game together? (Brainstorming) ???? It might deviate a bit from the current topic, but I don't want to start a new topic again.

Let's list the applications of the midpoint in various subjects.

I'll start with an example: (Planting a seed, ????)

Applications of the midpoint in Geometry:

1. Calculating Distance: When the coordinates of two points are known, the midpoint formula can be used to calculate the distance between them. Specifically, the midpoint formula states that the distance between two points is equal to twice the distance from their midpoint to each of the points.

2. Constructing Perpendicular Bisectors: The midpoint can be used to construct a perpendicular bisector, which is a line that is perpendicular to a line segment and divides it into two equal parts. Perpendicular bisectors are very useful in many geometric problems, such as constructing squares or hexagons.

3. Constructing Regular Polygons: The midpoint can be used to construct regular polygons, such as equilateral triangles, squares, and pentagons. Specifically, you can use the midpoint to construct the sides of the regular polygon, and then use these sides to construct the entire polygon.

4. Constructing Circles: When three non-collinear points on a circle are known, the midpoint can be used to construct the circle. Specifically, you can find the midpoint of these three points, which becomes the center of the circle, and then use the distance between any two of the points to determine the radius of the circle.