I haven't read any good books on Quintiles, but here are some posts on the subject by astrologers I respect:

Moses Siregar III had some blog entries on the subject:

"
A quintile is a 72 degree aspect. It's based on '5.' If you divide 360 by 5 you get 72. '5' resonates with Mercury more than any planet; it's creative and magical. Any time you have a quintile, those two planets combine to form some very powerful magic and gifts. They are more interesting and unique than trines and sextiles, though also somewhat more subtle. If you want to find someone's gifts in a chart, don't forget the quintiles. They are very special!

Let's hear it for quintiles!

Aloha,
Moses

Late addition 5/23/01

I now use an orb more like 5 degrees for quintiles after doing some research on this, and finding it to be true. As usual, though, the closer the aspect the more significant it is. A quintile around 5 degrees wide is still real to me, but not as powerful as a quintile within 1-2 degrees of orb.

Another addition 6/5/01

> Also, could you elaborate a bit on the article you wrote re: special 72 degree aspect (quintile?)

I find quintiles to be extraordinarily important, and to work very well up to about 5 degrees of orb. I think if you don't look for quintiles, you're leaving out one of the most positive indicators in a chart for someone's greatest gifts or blessings, and, of course, we need all the blessings that we can get. So, for the sake of being a positive-minded astrology-student or practitioner, I think it's imperative to spot the quintiles. I'd say treat quintiles like a trine, only more unique and special to the person. Quintile people, in general, are very creative and/or very mentally brilliant, whereas trine people, in general, are more laid-back and able to play and enjoy R & R. The negative of the quintile is being overly mental or active, while the negative of the trine is in being lazy or undisciplined or ungrounded. Since the quintile is based on '5' it makes sense to me that it should be given a wide orb. It's the most primary numerological aspect after the conjunction (1), opposition (2), trine (3), and square (4).

Aloha,
Moses"

Robert Wikinson wrote an article entitled

"Quintile, Tredecile, Decile, and Biquintile

There has been a lot written about the Quintile series of aspects, much of it vague and very generalized. Since these angles occur with great frequency, there is relatively little written about them, and a very important one is occurring at the present time, I thought I should offer you some insights about this misunderstood but very powerful series of aspects.

The entire series is based on division of the circle by 5, yielding 72 degrees as the primary aspect in the group, also known as the Quintile. This aspect represents specialization, gifts, and unique conditions. It is an aspect of creativity. No matter how similar it may be to other quintiles in other charts and times, each quintile is a unique quality or condition, a "quintessential" circumstance that has been weaved out of the "biospheric" responses of the "4" into the human "5th."

It represents a high degree of specialized force or form, something unique brought forth, transformed out of the generic materials. Thus it shows a point of high individualization, a unique stage of development, or a talent or gift recognized and/or articulated. All the other aspects in the series to some degree show this energy of specialization, just in different phases than the Quintile. I touched on this series, as well as the Septile series, in this article. And in Astrology Class - The Quintile, Biquintile, 5-Pointed Star Patterns, Kite Configurations, and Void Points I explain some possible ways the Quintile configurations can manifest.

For example the Decile, or Semi-quintile, is a 36 degree aspect showing a partly developed creative uniqueness, a minor gift, or some other manifestation of specialized creativity. It either secures a unique tendency, or is the final flowering of a gift already realized. The Biquintile, as the name implies, is a 144 degree aspect showing a unique interactive situation, where one gift interacts with another gift, creatively and/or regeneratively. It is an interactive unique form of self-expression that often involves other people and their unique gifts, whether they align harmoniously with yours or not.

Last but not least, we now take a look at the least-understood aspect in the series, the Tredecile, which precipitated this article for reasons I'll make clear shortly. This is a highly specialized aspect of 108 degrees, which besides being a mythological "Sacred number" symbolizing Divine Mother Energy, is also the complementary angle to the Quintile. Thus the Tredecile indicates a very special type of unique energy that complements whatever uniqueness, gifts, or specialized quintessence are occurring at the moment in a situation.

I have seen this aspect operate in several fashions, and all seem to involve a circumstance presenting itself that perfectly fits a unique gift or need, or a gift or unique quality that fits the need of a pre-existing circumstance. The Tredecile is complementary, interactive, and specialized, the "quintessence" of a thing perfectly complementing the "quintessence" of a circumstance. When active, it seems to bring forth unique qualities in situations that involve interaction to bring forth awareness, completion, polarization, or re-polarization. The points opposite the planets in Tredecile are often associated with how the energies manifest, some need being fulfilled, some promise brought to expression, or some specialized gift or talent completed.

I have given it the keyword "SERENDIPITY." I believe this is the best descriptor for how the Tredecile works its magic. So exactly what does this word mean? We are told the definition of Serendipity involves "the faculty or phenomenon of finding valuable or agreeable things not sought for" and "an aptitude for making desirable discoveries by accident" and "good luck in making unexpected and fortunate discoveries."

It is a word of relatively recent origin, invented by the noted author Horace Walpole in one of the more than 3,000 letters he wrote. Specifically, we read from dictionary.com that

In a letter of January 28, 1754, Walpole says that "this discovery, indeed, is almost of that kind which I call Serendipity, a very expressive word." Walpole formed the word on an old name for Sri Lanka, Serendip. He explained that this name was part of the title of "a silly fairy tale, called The Three Princes of Serendip: as their highnesses traveled, they were always making discoveries, by accidents and sagacity, of things which they were not in quest of...."

Back to the present as prologue: The rapidly separating Jupiter biseptile Saturn has now briefly slipped into the first of several Tredeciles between these two heavyweight planetary forces in our world. They show major shifts and phases in the larger socio-cultural life we all live in, and give us a sense of the larger forces we feel compelled to respond to. When they are in trine, forces are stabilized, When they are in square, forces are in dynamic change. When they are in biseptile, the world's governments and people confront forks in the road of collective destiny. What about the Tredecile?

When Jupiter tredeciles Saturn, it's a unique interactivity between complementary forces represented by these planets. In the life of a nation it works out several ways. In the life of a corporation, it works out in a variety of other ways. And in an individual life, it works out in many ways on both inner and outer levels.

It shows that our Sag and Pisces within us are now in a unique interactive relationship with our Cap and Aquarius parts. Any of our planets either of these aspect is subject to specialization, and if either of these form a Quintile, Decile, Biquintile, or Tredecile to any other planet, it lights up the points of a 5-Pointed Star pattern in our lives, a very special thing indeed.

This is the first of the three Tredeciles, and will last till the end of the month. The next one comes after the trine and occurs with Jupiter RX in late June and early July, just before the next Jupiter biseptile Saturn on its station beginning late July 2007. That biseptile lasts through early November, after which the third and final Tredecile between Jupiter and Saturn will take place the end of November and first half of December 2007.

Each of these times is conducive to highly specialized, unique, complementary interactions on every level, so take note, express your gifts, and you may just see the "quintessence" of a thing come forth. It's probably great for artists, scientists, and philosophers of all stripes, so stay alert for opportunities to bring forth unique and gifted things.

The 5-Pointed Star should come into acute focus when the Moon conjuncts Jupiter and tredeciles Saturn on Jan 15, deciles Jupiter and biquintiles Saturn on Jan 17-18, quintiles Jupiter on Jan 20, tredeciles Jupiter while biquintiling Saturn Jan 22-23, and biquintiles Jupiter while tredeciling Saturn Jan 25-26."

Danielle A. Ricard wrote an article entiled:

"The Power of 5 in Astrology

in the lives of Modern Legends of Music, Film and Politics

Often overlooked in Astrological practice, I have found the quintile to be extremely useful in assessing personality traits. Quintiles show in what areas of life one is powerfully driven. These 1/5th or 1/10 (of a circle) aspects between planets create compulsive tendencies imbedded so deeply in one's being that they can become insurmountable, uncontrollable behavior patterns. Quintiles may be quite upsetting if we're not aware of them! They often show personality traits that we can't seem to help or even understand. While this may sound daunting, I believe that Quintiles give us incredible strengths and powers that push us to succeed in whatever it is we are here on this earth to accomplish.

Much more compelling than the dynamic Square aspect, the quintile sends us beyond reason into areas of the psyche that don't care whether or not we conform to or fit in with others. Depending on the closeness of the aspect (by degrees in orb) and the planets or personal points involved, our behavior may become obsessive and uncontrolled. On the other hand, without such compulsions, many of us would flounder in a sea of mediocrity.

In esoteric tradition, 5 is the number of humanity. It represents the mind - that which empowers us to act for ourselves. The 5 represents self-serving, even magical powers. In Tarot - 1 is beginnings, 2 is partnership, 3 is birth, 4 is our foundation & security and 5 is the "unleashing" of our true nature. With the five, we find that we have "gone too far!" In the Tarot pip cards - the 5 of cups creates sorrow, wands creates discord, swords creates a feeling of being wrong and pentacles - material failure. They all seem grim, but they simply illustrate the tragic result of a lack of awareness for the power we wield.

When I discovered my big quintile - Moon 7th house/ Venus & Neptune 9th house - I was relieved to find out what made me behave sometimes irrationally in relationships. Very simply - when there is not harmony, I can't stand it! and I will persist in "making" my partner, friend, child (whoever!) be happy and pleased with me. Rejection is not acceptable... if I don't win my loved one over, I feel absolutely crazed! Knowing this has helped a great deal in recognizing how illogical and unreasonable I can become. I have slowly over the years worked at overcoming this aspect of my personality, and I am grateful to my brother for pointing out the importance of quintiles to me - (thanks Gary!). A less strong quintile between Mercury and Jupiter reveals my compulsion to uncover and learn as much as I can (hours spent at the computer!), and an even weaker quintile between the Moon and Mars hints at my need to act out my emotions immediately. Fortunately I have a strong Saturn that curbs my reactions somewhat. I have learned that these quintiles, while sometimes annoying, keep me on course. They add to my personal magnetism, and help assure that I do something of value every day!

So - enough about me. Here are some vastly more interesting people, sadly gone (I prefer not to write about the living without their knowledge!) who had some very interesting, and obviously fateful Quintiles!

In the chart of ultra Sagi Jimi Hendrix, there is a quintile between Uranus and the Midheaven - (career and reputation.) It is clear that Uranus - the planet of inventiveness, ingeniousness and wild rebelliousness, as well as electricity - compelled Jimi to express himself in a radical way for all the world to see. Also, the Moon quintile his Sagittarius rising drove Jimi to display his very changeable Cancer-Moon emotions immediately, honestly and in all that he did. A Saturn/Part of Fortune quintile clearly shows his compulsion to succeed.... in fact, it was beyond his control!

Here is some text from my Star Maps for Princess Diana who had Saturn in the 1st house (self-image) quintile Mars in the 8th (power, inheritance, etc...) "You are driven to act in accordance with social norms. You do not tolerate sudden changes or improper action. You feel a need for authority and discipline in your life, and would fit well into a highly ritualized, austere or martial environment." This - her strongest quintile aspect - hallmarked her position in life, and clearly marked her stubbornness in the face of such an unsatisfying marriage. Venus quintile the Part of Fortune and Neptune quintile the North Node contribute strongly to her incredible capacity for unconditional love and compassion, and her highly charitable nature.

In the chart of Marilyn Monroe, there is a very strong quintile between the Moon and Pluto. She had to express her emotions in a way that affected others very deeply, sexually and transformatively. For Marilyn, the Moon in Aquarius in the 7th house gave her a coolness that was very captivating, and with Pluto in quintile aspect, there was a tendency to either control or be controlled by relationships. She also had the same Venus - 9th house / Moon 7th house quintile that I'm blessed with (haha) - a compulsion to love and be loved, and a quintile configuration with the Sun between Uranus and Neptune. She was definitely "out there!" - totally unconventional, new, and in love with everyone and everything.

John Lennon's Sun in Libra quintile Pluto/Chiron in Leo (5th house) shows an overwhelming desire to create healing change and harmony for the world - through creative, sexually magnetic, explosive and revolutionary means. A (generational) quintile between Pluto/Chiron and Uranus adds to the sudden shock value of the 60's Peace-wave he symbolizes in so many ways, and an added quintile from Uranus to the Part of Fortune shows how he was truly fated to create lasting and revolutionary changes.

Quintiles abound in the chart of John F. Kennedy. A pivotal point is his 8th house Sun/Jupiter/Mercury/Mars stellium in Gemini and Taurus - all quintiling Libra Rising, Neptune/Saturn 10th, and Chiron 6th. Roughly translated, this amounts to a very high profile, powerful person driven to communicate and act upon his extremely lofty ideals - through any means at his disposal. His 11th House Aquarius Moon quintiles Pluto in Cancer in the 9th as well, illustrating well his emotional need for power and recognition, and to create drastic change.

Joan Crawford (remember Mommy Dearest?) was a doozy. Her already harsh 3rd house Moon/Saturn in Aquarius formed a lovely quintile to Neptune in the 8th house. She clearly visualized an illusory world where the expression of, and demands regarding her emotional needs were paramount to her power and success. Further, she had Pluto in the 8th house quintiling the Sun - heightening her obsession with control. I'll stop here, the rest of the quintiles only make it worse!

In the chart of Billie Holiday, there is a very strong quintile configuration linking the Sun, Pluto/Saturn, the Ascendant and the Midheaven in Scorpio. This illustrates beautifully her powerfully sexual presence, as well as her attraction to dangerous underworld characters and situations.

To end on a hopeful and spiritual note, our dear Dr. Martin Luther King Jr. used his quintiles for the most noble of causes. His ambitious Sun in Capricorn forms a focal point in a Sun/Neptune/Mars quintile, driving him in the direction of Spiritual Warrior and Government Reformer. Eleventh house Mercury in Aquarius is quintile Aries Rising - adding the gift of inspired and socially conscious speech as an integral part of his image. Jupiter quintile Pluto made his beliefs grandiose and life-transforming. This also gave him a huge does of sexual magnetism. These are just some notable quintiles among several other 5th harmonic aspects in his chart!

NOTES: In the above examples I have referred to both biquintiles and quintiles as Quintiles. I would not say that any of these great people were unaware of their power and charm, but I would imagine that they probably found it to be a burden. Although quintiles play a big role in each of their charts, these examples represent only a part of their complexity as human beings.

Robert Nesta Marley was an Aquarius, with Sagittarius Rising. His Venus 4th house opposite Neptune/Jupiter 10th illustrates the great love and spiritual devotion he gave to his people and to the world. Quintiles as a driving force behind his contribution are seen between the Moon in Scorpio - 12th house and Saturn in Cancer - 7th house. He felt driven to take his feelings quite seriously. He must have felt that humanity(12th house) was his partner in life (7th house) to be cared for and nurtured. Mars in Capricorn - 2nd house quintiles Venus - 4th house in Aries. Here we see partnership, love and art inspired with tremendous creative energy and drive to succeed. The North Node 8th house quintiles Chiron 10th house - showing his deep need to connect with people who are suffering in their self-esteem, politically, sexually or spiritually. Finally, the Sun is in very tight quintile with the Midheaven, attesting to his rise to world fame and recognition.

Leo Mae West's chart is loaded with dynamic quintiles. Her Cancer Moon - 2nd house quintiles Mars in Aquarius - 10th - a pivotal planet for her entire chart. This shows how her very nurturing emotional nature was expressed with great drive and energy. Saturn and Venus are quintile, and there is a quintile pattern between Pluto/Neptune, Chiron/Sun and Uranus - all in the personal houses. Not knowing a great deal about her personal life, I would say that she suffered in her self-esteem to a certain degree, and experienced hard-knocks in love. She clearly had an unusual, powerful and rebellious approach to sexuality. She likely felt unusual or outcast (Uranus) but had a very powerful spiritual and imaginative nature that she used to make herself visible in the world.

Bruce Lee was an amazing individual whose rise to fame was inevitable with Sun Rising in Sagittarius quintile the Midheaven. Uranus in Taurus - 6th house quintiles Pluto and Chiron in Leo - 8th house. Here we see his unstoppable drive to express his power through shock value, rebellion and unusual/ingenious, lightning fast means... and his dedication to his work. Mercury/Moon and Part of Fortune in Scorpio - 12th house quintile the South Node in Aries - 4th house. This indicates to me a sharp, witty tongue that might have gotten him into trouble on his home turf. He was probably good at hiding his thoughts, and striking unawares... So much Scorpio and Taurus in this stinging bull!! Bruce Lee was born to be an athlete, a fighter and a legend.

Sagittarius Jim Morrison had numerous quintiles. His Moon in Taurus 3rd house was pivotal with Neptune in Libra - 8th house and Sun - 10th. This first configuration helps to explain his Venusian Godliness, as well as his extremely spiritual, imaginitive and idealistic loving/sexual nature, and his emotional/energetic artistry, too. Mercury 11th quintiles Pluto/N.Node 6th, which oppose the Ascendant. He was compelled to express his power, magnetism & sexuality through thought & words, immediately, deeply and as a service to humanity - a powerful poet. Venus 9th quintiles Uranus/Mars in the 4th house. Here we see an erratic, open, freedom loving quality to his relationships. Finally, Chiron 7th quintiles the MC, PF - 5th and S.Node/Ascendant. This shows an inner pain, possibly having to do with his identity and men or masculinity (squares to Sun and Mars) that he needed to express, and that helped carry him to fame.

In the chart of Capricorn Janis Joplin, a prominent quintile between the Moon in the 5th house (Cancer) and Venus/Mercury in the 12th shows that compulsion to love and be loved that Marilyn Monroe had, but with Janis the focus is on expression, recreation and transcendence as opposed to partnership and wisdom. It's interesting that Venus is otherwise unaspected - possibly attesting to her loneliness in love. Jupiter in the 5th house is in a quintile configuration with Neptune in the 7th and the Ascendant. Here we see how her tremendous idealism and joy for life were overwhelmingly evident in all that she did. Chiron opp. AS/S.Node and Pluto/PF opposite Sun 12th contributed to her wounded self-image and tragic attraction to the dark side.

Here's a look at our sweet Aquarian clown, John Belushi who had a few interesting quintiles, too. Chiron 11th quintiles Mercury/Mars/PF 2nd which then connects to the North Node in Taurus. This shows a past wounding in his ability to express himself, along with a strong need to connect with others and express/act out inner suffering... certainly something he did in spades, and profited from, too. Trines to Uranus and Neptune contibute to his strong imaginative/creative/innovative abilities. Underworld Pluto in the 8th house quintiles MC/S.Node - showing a visible attraction to the dark side which proved to be his fame as well as his undoing. Is it any surprise that the Moon was rising when he was born?"