Pinpoints of Pathology
One modern technique that's extremely valuable in Medical Astrology is that of midpoints. The use of planetary midpoints in astrology was brought to a high level of development and perfection by Reinhold Ebertin and his Cosmobiology school, also known as Uranian Astrology.
A midpoint is the point midway, or equidistant between two planets or points in the natal horoscope on the shortest arc or angular distance between them. Because it divides the arc between two planets into two equal halves, a midpoint is similar in its essential dynamics to an opposition. But whereas not all planets in the natal horoscope are in opposition, every pair of planets or points has a midpoint.
Midpoints are the points of balance or interface between the physiological functions indicated by the two base planets or points. Like the opposition, a midpoint shows where the balance or homeostasis of the organism is challenged and vulnerable to pathology - but only if it's active.
For a midpoint to be active, it must form a hard Uranian aspect to another planet or important point in the natal horoscope. The Uranian aspects are the conjunction, square, opposition, semisquare and sesquiquadrate. To be active, these aspects must be within an orb of 1.5 dgrees or less.
The midpoint and the planet or point it targets or activates form a kind of equation known as a midpoint equivalency. The midpoint itself symbolizes the tension or conflict between the two physiological functions represented by the base planets, and the planet or point targeted is the focus of that conflict or disharmony.
In some midpoints, the base planets themselves are activated by the midpoint. These midpoints are called self-reactive. In such cases, the base planets themselves are usually in hard aspect, with a very tight orb. And so, midpoints have a lot in common with the conventional hard aspects.
The Sun / Moon Midpoint
The most important midpoint in astrology, medical or otherwise, is the Sun / Moon midpoint. Medically, it represents the focal or balance point between metabolic Fire and metabolic Water. Psychically, it represents the focal point or essence of your personality and its expression.
The sign placement of your Sun / Moon midpoint will show the overall character and essence of your metabolism. If it's in Cancer, for example, the overall character of your metabolism will be Phlegmatic; if it's in Aries, it will be Choleric. The house placement of your Sun / Moon midpoint will show which life area is most essential to your happiness, health and wellbeing.
The planet activated by your Sun / Moon midpoint will be central to the overall health and soundness of your metabolism. If this planet is challenged, debilitated or afflicted, it will represent key health problems to be overcome; if it's strong and well-placed, it will represent a bulwark of health and vitality.
Mars / Neptune: The Immune Midpoint
Mars concerns the overall strength and vitality of the immune response, whereas Neptune shows immune weaknesses and vulnerabilities. The point of balance or interface between the two is the Immune Midpoint. The planet targeted by the Immune Midpoint represents an organ or function that is immunologically challenged, or whose immunity is weak.
Jupiter / Saturn: The Metabolic Midpoint
Jupiter and Saturn are important regulators of metabolism, with Jupiter favoring Sanguine excess and Saturn favoring Melancholic deficiency. Where they meet represents the balance point of the overall nutrition and metabolism of the organism. The planet targeted by Juppiter / Saturn represents a critical organ or function that's problematic in the overall metabolic and nutritive balance of the organism. Its placement, debilities and afflictions, if any, will give further clues as to the nature of the metabolic imbalance.
The Humoral Midpoints
We all have our own innate constitutional balance or makeup of humor and temperament. Health consists of being in balance with our original constitutional nature.
What the humoral midpoints indicate is not our constitutional makeup, but rather a tendency towards excess or aggravation of a certain humor, with its associated pathological manifestations. With the Choleric midpoint active, for example, there will be a tendency towards biliousness, fever, inflammation, etc...
If a humoral midpoint targets or activates a third planet, that planet represents an organ, function or body part that's the focal point of the pathology in question. If the Choleric midpoint targets Jupiter, for example, the liver would be the focal point of Choleric pathology; with Saturn activated, it would be the spleen, or perhaps the bones, joints and connective tissue.
Often, the two base planets themselves are targeted or activated by the humoral midpoint. In these cases, the two base planets are usually in hard aspect themselves. And so, hard aspects between the base planets themselves are reliable and specific indicators, or signatures, of pathological predisposition. In these cases, the humor itself is problematic, and subject to morbidity and pathology. The sign and/or house placement of the midpoint itself will give further clues as to which organs or parts of the body might be affected when both base planets are activated. The sign placements concern natal or innate conditions, whereas the house placements concern those that become manifest later on in life.
The base planets of a humoral midpoint are those whose basic nature and temperament pertain to the humor in question. The humoral midpoints are as follows:
Sun / Mars: The Choleric Midpoint
Venus / Jupiter: The Sanguine Midpoint
Mercury / Saturn: The Melancholic Midpoint
Moon / Neptune: The Phlegmatic Midpoint
The Axial Midpoints
Planetary oppositions in the natal horoscope align along pairs of opposing signs called Medical Axes, which higlight domains of pathology. The Axial Midpoints are those whose base planets rule or disposit the pairs of opposing signs involved in the Medical Axes. They pertain to the same domains of pathology as their corresponding Medical Axes. The Axial Midpoints are as follows:
Mars / Venus (Aries / Libra) - The Renal Midpoint
Venus / Pluto (Taurus / Scorpio) - The Generative Midpoint
Mercury / Jupiter (Gemini / Sagittarius) - The Respiratory Midpoint
Moon / Saturn (Cancer / Capricorn) - The Nutritive / Structural Midpoint
Sun / Uranus (Leo / Aquarius) - The Circulatory Midpoint
Mercury / Neptune (Virgo / Pisces) - The Digestive / Immune Midpoint
As with the humoral midpoints, the Axial Midpoints can also be self-reactive, and are stronger indicators of axial pathology when they are. Here again, all this points to the power of hard aspects as indicators of pathological potential and stress.
Other Important Midpoints
There are several other important midpoints that the Medical Astrologer must assess when analyzing the natal horoscope. The major ones are as follows:
Jupiter / Neptune
The point of toxicity and intoxication. Indicates toxicity in the liver; also a tendency towards addiction or intoxication with drugs and/or alcohol. The targeted planet will indicate an organ, function or body part that's particularly vulnerable to the intoxication, toxicity or addiction.
Jupiter / Pluto
Associated with cysts, tumors, and abnormal growths. Jupiter indicates expansion and growth, and Pluto malignancy. The planet targeted represents the vulnerable organ or body part.
Saturn / Neptune
According to Medical Astrologer Marcia Starck, this is one of the most important midpoints in the entire natal horoscope. The planet it targets or activates will represent an organ or function that is chronically weak or vulnerable in the organism.
Venus / Neptune
This midpoint is associated with chronic infections of the female organs. It can also indicate putrefaction or fermentation in general, since Venus is associated with fermentation and Neptune with molds, yeasts, and fungi.
Mars / Saturn
The point of obstruction or blockage. Can also indicate great structural stress, injury or trauma. Choleric Mars excites and spurs onwards, whereas Melancholic Saturn obstructs and inhibits.
Mars / Uranus
Associated with accidents, injuries, trauma. Planet targeted can represent an organ or body part that's vulnerable to trauma or injury.
Mars / Pluto
Can indicate, malignancey, cell death, destruction of tissue, with planet targeted representing the focal point of this pathological potential.
Transits to Midpoints
In the beginning of this article, I introduced midpoints as being a highly specialized type of hard aspect. Although that's one way of looking at midpoints, midpoints are also sensitive trigger points that can be activated by transits and progressions to them just like any other planet or major point in the horoscope. And so, the pathological potential indicated by a midpoint in the natal horoscope can remain dormant until activated into manifest pathology by a major progression or outer planet transit. But in order for there to be pathological potential, either latent or manifest, the midpoint in question must target or activate either the base planets themselves or a third planet.
Internet Resources on Midpoints
According to my research, there are a lot of articles on midpoints up on the internet, but the vast majority of them seem to be of a very general or introductory nature. And the sources of reliable, specific information when it comes to midpoints in Medical Astrology seem to be even scarcer and harder to find. Perhaps the best and most detailed material on the use of midpoints in conventional astrology is on the site www.cafeastrology.com . Marcia Starck has some good material on midpoints in her book, Medical Astrology: Healing for the 21st Century, which is self published by her and available off her website www.earthmedicineways.com.
But if you really want to go back to the source, get Reinhold Ebertin's classic reference work on the subject, the midpoint bible: The Combination of Stellar Influences.