What is Astrology?

The intent of this document is to answer common questions I get about how I conceive of astrology and why I think it's cool and useful.

Basic Concepts

  • Astrology is a description language for agentic systems, a vocabulary of symbols which describe features and a grammar for relating them.
  • Astrology is a divination framework, for producing meaningfully patterned data from a random seed. As with all types of entropy generation, this is where astrology draws from physics, specifically astronomy.
  • A chart is a randomly produced system describing an agent's set of internal motives and tensions.
  • A natal chart is a chart generated for a person's birth time and place, which is said to represent them. Its interpretation in terms of personality and behavior is known as psychological astrology.

Why Divination?

  • Overcoming our preconceived ideas of anything we're trying to learn about is a hard problem, particularly for introspection. By forcing the "reader" to fit objective observations into a randomly generated system, they become able to observe potentially novel patterns, ones previously overlooked due to their subjective attachment to already recognized patterns.
  • As a metaphor, consider how drawing a face "objectively" is easier when the source image is upside down. The forced reorientation produces a shift in how one subjectively relates to the thing presented: the familiar becomes once again unfamiliar and thus open to reinterpretation.
  • The class of divination tools includes many "esoteric" practices such as tarot, i ching, and augury, with the common thread being the use of randomness to gain perspective.

What's In Astrology?

  • The vocabulary consists of planets, signs, and houses, rendered as degrees or contiguous sets of degrees.
  • The primary grammar consists of aspects relating planets based on degree, as well as relationships inherent in the symbols themselves, such as rulerships.
  • Certain positions, such as the "cusp" or beginning of the first house, called the ascendant, have special names and qualities. Certain higher-order patterns do as well, like a t-square or stellium.

Two Ways of Speaking

Astrology as Internal System.

  • Planets are sub-agents with distinct urges and needs, representing the entire psyche when considered as a whole. Each sub-agent acts with a particular modality or orientation according to sign, and in a particular sphere of existence, or house. Aspects determine the quality of relationships between planets, whether ease or tension.
  • e.g. "Venus in Taurus wants to connect with others physically and possessively, but she is in tension (square) with Saturn in Aquarius, who wants to abide by abstract social rules."
  • The introspective task becomes identifying patterns in your life in which these sub-agents make their appearances and stage their desires or dramas.

Astrology as External System.

  • Planets are needs within a singular person, which manifest with particular qualities (signs) and in certain kinds of situations (houses). Aspects determine the harmonious or ambivalent relationships between needs.
  • e.g. "My Venus in Taurus means I want to connect with others physically and possessively, but that's in tension with my Saturn in Aquarius, my desire to construct and follow abstract social rules."
  • The introspective task becomes identifying certain sets of needs or desires which relate to the planets, and understanding how they may be blocked or facilitated by their relation to other desires (or lack thereof).

What's The Point?

  • In both cases, the goal is to discover ways to resolve felt tensions by understanding the overarching system and enacting changes, in thought or action, which facilitate or maintain good outcomes and avoid or prevent bad ones.
  • A key feature of astrology is that it is non-pathological, so even the challenges produced a "difficult" chart can be overcome through understanding and effort.
  • What I mean by this is that there's no concept of "healthy" vs "unhealthy" within the astrological framework itself, only gradations of tension with a system. High tension systems can produce great results. It is up to the reader to determine what the intent of the system, in this case of living, is: astrology is not a moral theory. This is in contrast to most psychology which sets out from a medical framework and aims to achieve some predetermined notion of "health".
  • The downside, as with any psychological framework, is becoming overly attached to one's self-definition, and using it as a tool to rationalize problems and thus avoid confronting them.
  • Astrology has tools to help avoid getting overly attached, such as progressions (shifting the planets based on their motion as you age) and transits (comparing present planetary positions with your chart), which introduce additional randomness and novelty over time.
  • Astrological principles can also be used as a tool to describe abstract systems such as cities or states or corporations (mundane astrology), and can also be used for comparing two systems or individuals (synastry), and answering questions (horary astrology) or making decisions (electional astrology).

Appendix: Some Definitions

  • As with any language, a word's referent is not easily explained through description. I can tell you a tree is a large plant with a trunk and green leaves, but you wouldn't really know what I meant until you saw a tree first-hand. This is part of the difficulty in learning astrology: figuring out the meanings of symbols through experience.
  • I can, however, provide some brief keywords or descriptions as a first step toward understanding, mostly taken from Margaret Hone's "Modern Textbook of Astrology" and Stephen Arroyo's "Astrology, Psychology and the Four Elements".
  • In the previous section, I laid out the form and context of astrology without getting into the content. This section is only for those interested in digging a bit more deeply into what exactly are the planets, signs, houses, and aspects. Images and tables help, and regrettably I don't have those to offer. I suggest consulting a more thorough reference if you want an even deeper dive.


Planets represent specific patterns of systematic tendencies in relation to a singular entity. As described earlier, planets manifest to the "subject" as needs or urges, but can also be viewed as agents within the system.

  • Sun (☉): power; vitality; self-expression. Urge to be and to create. Need to be recognized and to express self.
  • Moon (☽): response; fluctuation. Urge to feel inner support; domestic and emotional security urge. Need for emotional tranquility and sense of belonging; need to feel right about self.
  • Mercury (☿): communication; the mind; short journeys. Urge to express one's perceptions and intelligence through skill or speech. Need to establish connections with others; need to learn.
  • Venus (♀): harmony; unison; relatedness. Social and love urge; urge to express affections; urge for pleasure. Need to feel close to another; need to feel comfort and harmony; need to give of self's emotions.
  • Mars (♂) energy; heat; activation; desire. Self-assertive and aggressive urge; sex urge; urge to act decisively. Need to achieve desires; need for physical and sexual excitement.
  • Jupiter (♃): expansion; preservation; grace. Urge toward a larger order or to connect self with something greater than self. Need for faith, trust, and confidence in life and self; need to improve self.
  • Saturn (♄): limitation; cold; contraction; effort. Urge to defend self's structure and integrity; urge toward safety and security through tangible achievement. Need for social approval; need to rely on one's own resources and work.
  • Uranus (♅): change (revolutionary; disruptive; dictatorial); individualistic freedom. Urge toward differentiation, originality, and independence from tradition. Need for change, excitement and expression without restraint.
  • Neptune (♆): nebulousness; imagination; unification. Urge to escape from the limitations of one's self and of the material world. Need to experience a oneness with life, a complete merger with the whole.
  • Pluto (♇): transformation; elimination; regeneration. Urge toward total rebirth; urge to penetrate to the core of experience. Need to refine self; need to let go of the old through pain.

Signs, Elements, Triplicity

Signs are derived as pairs of element (fire, air, earth, water) and triplicity (cardinal, fixed, mutable) and represent modalities, "shapes" or patterns of organizing energy.

The Elements

  • Fire: universal radiant energy, which is excitable, enthusiastic, and which through its light brings color into the world. Experience centered in personal identity.
  • Air: energy relating to the world of archetypal ideas behind the veil of the physical world, energy actualized into specific patterns of thought, geometric lines of force functioning through the mind. Experience concerned with theoretical relations.
  • Water: deep emotion and feeling responses, from compulsive passions to overwhelming fears to all-encompassing acceptance and love of creation. Intuition, sensitivity, vulnerability; deep soul yearnings; attunement to the unconscious.
  • Earth: the physical senses and the here-and-now reality of the material world. Practical reason, patience, self-discipline, endurance and persistence. Cautious, premeditative, conventional, dependable.


  • Cardinal: centrifugal energy; action in a definite direction.
  • Fixed: centripetal energy, radiating inward toward a center; inertia.
  • Mutable: spiralic energy; harmony, oscillation.

The Signs

  • Aries (♈︎): cardinal fire, ruled by Mars. Single-pointed release of energy toward new experience. Self-willed urge for action, self-assertion.
  • Taurus (♉︎): fixed earth, ruled by Venus. Depth of appreciation related to immediate physical sensations. Possessiveness, retentiveness, steadiness.
  • Gemini (♊︎): mutable air, ruled by Mercury. Immediate perception and verbalization of all connections. Changeable curiosity, talkativeness, friendliness.
  • Cancer (♋︎): cardinal water, ruled by the Moon. Instinctive nurturing and protective empathy. Feeling, reserve, moods, sensitivity, self-protection.
  • Leo (♌︎): fixed fire, ruled by the Sun. Sustained warmth of loyalty and radiant vitalization. Pride and urge for recognition, sense of drama.
  • Virgo (♍︎): mutable earth, ruled by Mercury. Spontaneous helpfulness, humility & need to serve. Perfectionism, analysis, fine discrimination.
  • Libra (♎︎): cardinal air, ruled by Venus. Harmonization of all polarities for self-completion. Balance, impartiality, tact.
  • Scorpio (♏︎): fixed water, ruled by Mars (traditional) or Pluto (modern). Penetration through intense emotional power. Compulsive desires, depth, controlled passion, secrecy.
  • Sagittarius (♐︎): mutable fire, ruled by Jupiter. Restless aspiration propelling one toward an ideal. Beliefs, generalizations, ideals.
  • Capricorn (♑︎): cardinal earth, ruled by Saturn. Impersonal determination to get things done. Self-control, caution, reserve and ambition.
  • Aquarius (♒︎): fixed air, ruled by Saturn (traditional) or Uranus (modern). Detached coordination of all people and concepts. Individualistic freedom, extremism.
  • Pisces (♓︎): mutable water, ruled by Jupiter (traditional) or Neptune (modern). Healing compassion for all that suffers. Soul-yearnings, idealism, oneness, inspiration, vulnerability.


Houses represent concrete domains of experience in relation to the life of the system or person under consideration. All house systems contain 12 houses, and they are classified as angular (action/gaining), succedent (security/maintaining), and cadent (learning/loss), in that order, in 4 groups.

  • Houses are the subject of more debate in terms of meaning than the planets and signs. Stephen Arroyo follows "the founder of modern astrology", Alan Leo, in grouping them in terms of trines, meaning groups of houses at 120 degree angles from each other, and also in associating them somewhat with the elements. Arroyo classifies houses 4, 8, and 12 as "water houses" dealing with "soul and emotional" experiences, houses 10, 2, and 6 as "earth houses" dealing with "material" experiences, houses 1, 5, and 9 as "fire houses" dealing with "identity" experiences, and houses 7, 11, and 3 as "air houses" dealing with "social and intellectual" experiences.
  • Other astrologers have different ways of dividing the houses, sometimes using 1-2-3, 4-5-6, etc instead, and others focused on oppositions, e.g. Noel Tyl who calls the opposite houses 3 and 9 the "axis of the mind".
  • The specific mathematical system for deriving house locations is also a subject of much debate. Whole sign houses line up the house cups with the sign cusps on the zodiac, making it the simplest option. Equal houses use the same house sizes as whole signs but starting at the ascendant. Placidus subdivides the zodiac using quadrants via the Ascendant and Midheaven axes. It is currently the most popular house system because it was in vogue at the time a famous astrology pamphlet was printed in the 1600s. Co-Star uses Porphyry, an older house system it arbitrarily prefers over the others.

Here is an extremely basic description of the houses from Margaret Hone:

  • 1 (angular): the whole person (this is also the Ascendant or "rising sign").
  • 2 (succedent): possessions and feelings of the person.
  • 3 (cadent): short communications. mental interests. nearest relations such as brothers and sisters. neighbors.
  • 4 (angular): home (base), enclosed spaces.
  • 5 (succedent): creativity, risks, pleasures, love, children.
  • 6 (cadent): service; in work, in health.
  • 7 (angular): others in close connection.
  • 8 (succedent): possessions of or from others. legacies, shared feelings. the life-force in birth, sex, death, and after-life.
  • 9 (cadent): longer communications. more profound mental interests.
  • 10 (angular): matters outside the home. public standing. attainment.
  • 11 (succedent): more detached contacts such as friendships. objectives, "hopes and dreams".
  • 12 (cadent): more secluded service. retirement; escape; sacrifice; hidden life of the unconscious.


Aspects are angular relationships between planets. They are typically classified as being "easy" or "difficult" based on whether they produce ease of energy flow or tension between the two planets. Tension is not necessarily bad, as it creates a reservoir of energy which can produce great results if an outlet is found. Similarly, ease is not necessarily good, as it can create laziness and lack of motivation.

  • Conjunction (☌): 0 degrees, neutral, the two planets' energies blend.
  • Opposition (☍): 180 degrees, difficult, the two planets oppose each other and must find a balance (signs have same triplicity, same "gender").
  • Square (□): 90 degrees, difficult, the two planets are in tension and have trouble working together, but the difficulties can be overcome through synthesis (signs have same triplicity, opposite "gender").
  • Trine (△): 120 degrees, easy, the two planets work very well together (signs have same element, different triplicity).
  • Sextile (⚹): 60 degrees, easy, the two planets work fairly well together (signs have different elements but are compatible).

Since they act as a sort of connective grammar across a chart, reading aspects in combination with all of the above can be a very complex task, and requires a lot of practice and skill to do cleanly, especially when considering the chart in its totality.

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