A Brief Introduction to the Harmonic Aspects Method
by Michael Freedman

Throughout the 20th century, astrologers have tended to increase the range of the different kinds of aspects which they use. However, outside of Harmonic Astrology, initiated in around 1950 by John Addey, the use of anything other than Major and Minor Aspects has been sporadic, not organized and largely a matter of personal preference.

The situation generally has been that some astrologers take notice of quintiles, while others look at septiles and so on. This is possibly due to the fact that many astrologers have difficulty even finding quincunxes or sesquisquares in an astrological chart, let alone quintiles or septiles.

There is also another, more important reason, to be discussed shortly, why most astrological attention has been largely confined to the Major and Minor Aspects.

The concept called the Harmonic Aspects Method provides techniques for handling any aspects of whatever kind. The word "Harmonic" has been used because the principles of the Harmonic Aspect Method are similar to some of those used in Harmonic Astrology, although its techniques are different.

  1. Both the Harmonic Aspect Method and Harmonic Astrology regard every planet in a horoscope as in aspect to every other planet. Every link between every pair of planets in a horoscope has some significance.

  2. Both the Harmonic Aspect Method and Harmonic Astrology regard aspects as the result of the division of the horoscope circle by whole numbers.

  3. Both the Harmonic Aspect Method and Harmonic Astrology use the finding of John Addey that traditional esoteric teachings on the significance of numbers provide clues to the meanings of the various series of aspects.
However, apart from these points, the techniques of horoscope analysis and interpretation associated with the Harmonic Aspects Method are otherwise much closer to traditional astrological methods than to those of Harmonic Astrology.

The Harmonic Aspect Method does not add any more factors to a horoscope. What it does is look systematically at all those aspects which are already there.

Angular Separation

The commonest kind of astrological chart is a map of the heavens at the time for which it is drawn up, viewed from a specific place on earth. It is possible to cast a chart for a current time at night, take it outside and use it to locate any planets that happen to be above the horizon. Use the chart to find two planets, then hold up your arms and point one hand at each planet. The angle made by your outstretched arms is a rough indication of the angular separation between the two planets.

When angular separation between a pair of Planets is close enough to one of those angles which divide the circle by a whole number, it is called an Aspect. A typical example of an Aspect is a Trine, when two Planets are about 120 degrees apart. Three planets each about 120 degrees from the others divide the circle into three approximately equal parts. Squares divide the circle by four; Sextiles by six; Quintiles by five; Undeciles by eleven; and so on.

Harmonic Aspect Series

All the members of an Aspect Series are made by dividing the circle by the same Harmonic Number. In theory, but not in practice, there are the same number of aspects in an aspect series as its Harmonic Number. For example, in theory there are three aspects based on the number Three: 1/3; 2/3; 3/3. However, the Third Harmonic Series in practice has only one member, the 1/3 aspect of 120 deg., called a Trine. This is for the following reasons.

  1. When the angular separation is measured between two planets lying on the zodiac circle, we can measure either the shorter distance between them or the longer. It is astrological practice to measure only the shorter distance. Two planets 240 degrees apart measured the longer way, are 120 degrees apart measured the shorter way, so that angular separations of 120 degrees and 240 degrees are both described by astrologers as 1/3 or a Trine.
  2. Although the 3/3 aspect is part of the Third harmonic aspect series, it is actually a Conjunction or 1/1 aspect. It is usual practice among astrologers to describe an aspect by the smallest Harmonic Number which describes it. For example, 180 degrees is both 1/2 of circle and 2/4. But we always refer to it as a 1/2 aspect (Opposition) never as a 2/4 aspect.

These principles are shown in operation very clearly in Table 1, where the 8th Harmonic Aspect Series is set out in detail, dividing the whole circle into eight parts. It can be seen that, in actual astrological practice, the 8th Series has only two members, the Semisquare and Sesquisquare, and not eight members, because two of the others are just these two going the other way round the circle. The other four belong to more fundamental aspect series than the Eighth.

Table 1: The Eighth Harmonic Aspect Series

1st member (1/8) 45 deg. Semisquare 1/8
2nd member (2/8) 90 deg. Square 1/4
3rd member (3/8) 135 deg. Sesquisquare 3/8
4th member (4/8) 180 deg. Opposition 1/2
5th member (5/8) 225 deg. Sesquisquare 3/8
6th member (6/8) 270 deg. Square 1/4
7th member (7/8) 315 deg. Semi-Square 1/8
8th member (8/8) 360 deg. Conjunction 1/1

Major And Minor Aspects

Astrologers have used the aspects formed by dividing the circle by 2 [Opposition], 3 [Trine], 4 [Square] and 6 [Sextile] for at least 2000 years. These four, plus Conjunctions, when two planets are within a few degrees, are called Major Aspects. Since the 17th century, astrologers have also used aspects formed by dividing the circle by 8 and 12. The latter are called Minor Aspects.

Table 2 lists all the aspects in common use during the past 400 years.

Table 2: The Major & Minor Aspects

Conjunction 1/1 360 degrees (12/12) (8/8) Major
Opposition 1/2 180 degrees (6/12) (4/8) Major
Trine 1/3 120 degrees (4/12) Major
Square 1/4 90 degrees (3/12) (2/8) Major
Sextile 1/6 60 degrees (2/12) Major
Semisquare 1/8 45 degrees (1/8) Minor
Sesquisquare 3/8 135 degrees (3/8) Minor
Semisextile 1/12 30 degrees (1/12) Minor
Quincunx 5/12 150 degrees (5/12) Minor

Notes To Table 2

  1. All Major and Minor Aspects belong to either or both the 8th and the 12th Series of Aspects.
  2. When two planets are 0 degrees apart, they are also 360 degrees apart, which is why Conjunctions belong to the First Series.

The Propositions Of Harmonic Aspect Theory

These propositions are an attempt to provide a working structure to handle a theoretically infinite number of harmonic aspects. They are offered as working propositions which are supported by nearly twenty years' personal investigation into aspect theory and practice.

Proposition 1

Every planet is in aspect to every other planet. What this means is that every Angular Separation between two planets potentially has significance for the person or event for whom the horoscope has been cast.

For example, let Venus be separated from Mars by 137 degrees 30 minutes 28 seconds. Only a few astrologers in the late 20th century would be comfortable treating this as a Sesquisquare (135 degrees), as it is beyond the 1 or 2 degrees orb most would allow. Therefore, most astrologers would ignore it, while even harmonic astrologers would be lucky to pick it up unless they happened to cast a 21st or 34th Harmonic Chart; or a 1597th Harmonic Chart, in which it would it is within 0.18 seconds of exact, that is, exact.

The Harmonic Aspect Method restricts itself, for good reasons discussed elsewhere to the first 36 Harmonic Aspect Series. It would regard the following as a full definition of this aspect:

Planets: Venus/Mars Angular Separation: 137d 30m 28s Primary Aspect: 13/34 37% strength Secondary Aspect: 8/21 13% strength: 0.04

What this description shows is that 137d 30m 28s is within orb of a 13/34 aspect, close enough to exact to have 37% of its potential strength. It is also within orb of an 8/21 aspect, but at only 13% of the potential strength it would have if exact.

13/34 is called the primary aspect, because it is the strongest aspect between Venus and Mars; 8/21 is the secondary aspect, because it is the weaker.

Proposition 2

A harmonic aspect is any division of the 360-degree circle which can be defined by a fraction in which both the numerator and the denominator are integers.

This proposition sounds more complex than it actually is. It merely states that you can redefine the angular separation between two planets, which is usually expressed in terms of degrees, minutes and seconds, in terms of a simple fraction, such as 1/2, 1/4, 5/12, 4/9 or 13/34. It has long been an implicit assumption of astrology that the denominator, not the numerator of such fractions reveals the nature and effects of the aspect on the planets linked by it. In the examples given, the denominator is 2, 4, 12, 9, or 34, and these numbers determine the principal characteristics of the aspect. Here, the numerator are 1, 1, 5, 4, or 13.

Over the centuries, astrologers have learned to distinguish between a 1/8 and a 3/8 aspect; or a 1/12 and a 5/12 aspect. But I doubt if there is yet any clear understanding of the difference between a 1/2 and 2/5; or a 1/10 and a 3/10, for example. As more people use aspects other than the Majors and Minors, so understanding will develop and differences noticed between, for example, the 1/11, 2/11, 3/11, 4/11 and 5/11 aspects. aspect on the two planets linked by it.

Proposition 3

Aspects become stronger as they approach exact; and their strength varies inversely as the square of the distance from exact.

The Method of Harmonic Aspects produces many more aspects than the traditional methods of astrology. You must be able to assess how much notice should be taken of any aspect in comparison with other aspects. Calculating the comparative strength of each aspect enables the astrologer to view them in perspective, taking more notice of stronger aspects and less of weaker aspects.

Because this paper was originally no more than the first chapter of my book on Harmonic Aspects, a point has not yet been made.

When using Harmonic orbs, the orb of every aspect is derived from the Conjunction orb, according to the following rule:

The orb of any aspect is the conjunction divided by the Harmonic of the Aspect.

If you set the Conjunction orb at 12 degrees, as I do, then the following table can be generated:

Conjunction 1H 12/1 = 12 degrees
Opposition 2H 12/2 = 6 degrees
Trine 3H 12/3 = 4 degrees
Square 4H 12/4 = 3 degrees
and so on.

If anyone is alarmed by the enormity of a 12 degree orb for a conjunction, consider that in this system the strength of an aspect is a vital consideration. If you are not taking much notice of any aspect below 10% strength, then the Orb of a conjunction is effectively 8 degrees.

Example: If an Opposition has an orb of 6 degrees and an Angular Separation is 175 degrees, then it is 5 degrees from exact. [6-5] divided by 6 = 1/6]= 0.1667. Square of 0.1667 = .0278 which is 0.03 to two decimal places. Expressed as a percentage, this aspect has 3% of its potential strength

The following Table sets out an indication of how to assess the comparative strength of any aspect from its Strength No.

100% Partile [exact] aspects are dominant factors in a chart
90% to 99% Powerful aspects; pay close attention to them.
70% to 89% Very strong aspects.
50% to 69% Strong aspects.
30% to 49% Fairly strong aspects.
10% to 29% Not strong; only occasionally have much effect
01% to 09% Weak; rarely have much effect, unless they are part of a larger structure.

Proposition 4

There are fundamental differences between the effects of the Major & Minor Aspects and those of all other Aspects.

An infinite number of Aspect Series can be formed by dividing the circle by a whole number of whatever magnitude, e.g. 5, 7, 9, 10, 11, 13, 37, 144, 180, 380, 1597 or any other number. Before the 20th century, aspects other than Majors and Minors were virtually ignored entirely,

It is a principal hypothesis of this article that the reason why the lesser known aspects have been virtually ignored is that there are basic differences between the psychological effects of major & minor aspects and all other aspects.


There are four levels of aspects, to one or more of which every angular separation belongs:

The phrase "Level of Effect" is not meant to be a precisely defined scientific term, but merely to give an indication of the way in which each group of aspects seem to correlate with levels of experience in the human psyche.

In practice, I rarely analyze a chart beyond the 12th Harmonic, except in the special case of Midpoint Structures. Unless the individual is engaged in some kind of depth analysis, to be told that they have this or that latent trait can only serve to confuse them. Unless they are willing and in a position to undertake guided expert exploration of their significance, this knowledge is of little use to them. On the other hand, mere knowledge of the potential aspects in a chart.. i.e. 5H quintiles, 7H septiles, 9H noviles, 10H deciles and 11H undeciles, is often enough to bring them into overt play.

Of the Potential Aspects, experience shows that the quintiles are by far the most Overt, indicating talents that a person is almost certain to develop.

Handling the Information Overkill

The major task for every astrologer is how to handle the vast amount of information generated by an astrological chart. Even using only the Sun, Moon and Planets, North Node, Ascendant & Midheaven, normally do, a full Harmonic Aspect analysis of any chart will yield 78 primary aspects, plus some secondaries. If Chiron and the four asteroids were added, there would be 153 primary aspects to interpret.

If you also use Midpoints and I find them very useful, especially when considering events rather than traits, the amount of information poured at the hapless astrologer is beyond handling.

The way I handle this problem is:

  1. I do not use any but the solar system planets and points, except in unusual circumstances, when the particular light thrown by Chiron or the asteroids is warranted. This would only happen if I knew enough about the individual already for me to consider it warranted.

  2. I use only the first 12 harmonics, i.e., the Overt and Potential aspects, unless the native is also undergoing depth analysis of some kind.

  3. I pay regard only to those midpoints where all three of the aspects involved are on the same harmonic, using all 36 harmonic aspect series. This means that the midpoint has to be very close to exact for it to be considered.

Summary of the Principles Of Harmonics Aspects Method

Proposition 1: Every planet is in aspect to every other planet.

Proposition 2: A harmonic aspect is any division of the 360-degree circle which can be defined by a fraction in which both the numerator and the denominator are integers, e.g., 1/2; 3/8; 4/9; 9/23; 55/144.

Proposition 3: Aspects become stronger as they approach exact. Their strength varies inversely as the square of the percentage of the distance of the planet from exactitude.

Proposition 4: There are fundamental differences between the effects of the Major & Minor Aspects and those of all other Aspects.

Proposition 5: There are four levels of aspects, to one or more of which every angular separation belongs: (1) Overt; (2) Potential; (3) Latent; (4) Instinctual.

Further papers are written or in preparation on Behavior Chains; and on the suggested interpretation of all Harmonic Aspect Series to the 37th Harmonic.

Copyright © Michael Freedman, S.G. 1996-2012, freedman@ihug.co.nz Re-posted here by permission of the author. This material may not be copied or passed on without permission having been given and due acknowledgment of its source.

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