• the principle of analogy or correspondence
• the conception of time´s quality and contents
• the conception of a numeral figure´s content or quality (the mainly geometric horoscope model)

Astrology has its law of analogy in common with all mantic or divinig methods. Its symbols are metaphoric; they are functioning like parables, relying on some parallelism between heaven and earth. Microcosm and macrocosm, inside and outside things are in accordance to one another - there is an essential equivalence, a special kinship on the level of sense and meaning. Yet, the kind of similarity between the things above and those below is not a fixed one; a constellation´s level of realisation or factual manifestation is not determined. Nature in this regard proves quite inventive, creative and manifold - though the phenomena observed always are consistent with the actual planetary configuration, i.e. all the things are happening according to the symbolic pattern lying underneath. You can´t prophesy an analogy´s concretisation in every detail; exactly testing and validating a constellation´s effects is quite fruitless an effort - for the cosmos is smarter than human mind in detecting and producing totally new equivalents...
The law of accordances doesn´t talk about causation; analogies don´t tell of unequivocal heavenly causes and earthly consequences. The principle of "above and below" is a descriptive one: by it the structure of the atmospheric powers, the diverse existing energies´ relations and connections just get formulated - yet, in an intricately differentiated way. (Therefore grasping and naming a constellation´s meaning is more useful and important than mentally or empirically analysing it.)
The reason why someone or something is reacting to the cosmic conditions usually is explained by natural philosophical terms like "affinity" or "resonance". The medieval myth of the music of the spheres (which is rooted in the Pythagoreen tradition) stated that the soul´s chords would sound whenever the planetary harp´s according ones were plucked. Modern authors say that the only things that can befall me are those which I am receptive or ready for, those that I am unconsciously attracted to. (So actually, "causation" goes the other way round, it doesn´t begin with the stars but with the unconscious self.)
Thinking in analogies is older than astrology; it´s at least older - and more important - than the astrologers´ referring to astronomical data. As T. Schaefer pointed out, historically the first chart - the Mesopotamian liver chart - didn´t need any stars and their diligent observation. Yet, those ancient liver-watchers already used an astrological system of correspondences!

Time´s quality is the second pillar astrology´s model based upon. This principle actually is the central axiom of every oracular method (like the I Ging, or the Tarot system). In this view time isn´t considered an empty container which may be filled with any content. It isn´t thought a river senselessly passing by, not a clock just ticking indifferently. Time is seen full of meaning, it´s some kind of a transcendent, unlimited reservoir; it´s felt pregnant with all potentialities, with all the seeds of creation - and in every moment one or the other is born or actualised. In this sense time may be equated with absolute being or eternity, whose otherworldly concentrated substrata get "unzipped" along this world´s quantitative time axis - thus becoming visible and seizable to everyone.
During a process of the time´s contents being manifested the astrologer´s eye is able to detect specific cycles and rhythms. He is so able to see some repetition of the same, extended or reduced, respectively (cf. the techniques of transits and directions) - though a constellation´s physical realisation each time may differ enormously. Yet, on the abstract level of sense and meaning there is no doubt about a moment´s contents - these are quite definite and clear. It's only the concrete manifestation which may put on many garments...
In astrological view events happening at the same time are interrelated in a non-causal way - a principle called "synchronicity" by C.G. Jung. Thus persons and things (or planetary cycles) are connected to one another; between them there is an inner correspondence or coincidence - though to a scientist´s eye they seem to have nothing in common. An occurrence´s time and place isn´t irrelevant or accidental; its specific attributes depend on hidden ("occult") processes and developments. Astrology´s code tries to decipher this cosmic bell´s toll.
Because of the principle of time´s quality the moment of birth is seen so crucial; the eminent moment of a being´s entering into earthly existence is telling the astrologer all about a person´s qualities and endowments. Like a vintage every individual born at a specific time is bearing this moment´s unique characteristics, its typical aura and flavour. In his progressing life the person is giving shape to his first cry´s moment´s special contents. "The beginning contains the end" the Emerald Table´s affiliated concept put this. This is an Uroboric idea (the snake biting its own tail), saying that a development´s starting point, its course and its results are inseparably bound up with one another. * (cf. note 1)

The quality of numerical figures is astrology's third central axiom. To a certain degree numerical quantities, i.e. enumerations and arithmetic procedures are necessary for astrologers - e.g. the tables of the ephemeris and the results of computer calculations being the basis of any interpretation. Yet - another Pythagoreen idea - figures and numbers predominantly are considered metaphysical entities - transporting some profound meaning.
Just like in numerology, number "one" stands for something whole and complete - so it corresponds to the sun and the aspect of the conjunction. Number "two" is symbolical of things splitted or separated, of something tossing back and forth - which also are typical features of the moon and the aspect of the opposition, and so on. Such qualitative view of numbers still was customary four hundred years ago - that´s why people thought the term "mathematician" a synonym of the astrologer´s profession.
Detailled geometry is the point wherein the knowledge of the stars is differing and distinguished from other mantic systems. Yet, the astrological conception altogether isn´t just a reflection of the firmament´s given or observed facts: the horoscope is sort of a typification, some stylized model of astronomical realities. Therein all heavenly bodies get related to the ecliptic - their factual declination or latitude doesn´t really matter. And the ecliptic is not depicted as an ellipse but as a perfect (Platonic) circle. We see criteria like proportion and symmetry that are decisive in astrology´s system. (In the beginning of modern times Kepler deserved greatest merits because of his sublime geometrical and harmonical explanation of the astrological aspects.) For aesthetical and theoretical reasons the sun´s annual path has been divided into twelve equal - ideal, not real - parts of exactly thirty degrees. Similarly the earth´s rotation has been dealt with: every day is seen consisting of twelve phases or houses (of approximately two hours). These duodecimal systems mathematically are composed of "three times four". In general, numeral "four" stands for structural categories of being, i.e. the elements and quadrants. Numeral "three" signifies dynamics - cardinal, fixed and variable (houses or signs); Doebereiner´s triple-step-evolution - jumping from the third to the first quadrant, then going on to the second and finally reaching the fourth - is another illustration of the numerals' inherent energetic moment and drive.
Whenever in a beginners´ course a student of astrology is counting a chart´s weight of the elements, this is already an engagement in astrology´s specific geometry. Whenever you simply differentiate the planets´ distribution dualistically - regarding right and left (of the meridian), above or below (the horizon), positive-negative, active or passive - this is the first step to interpretation. For in astrological thinking these simple numerical categories (one, two, three, four...) are coupled with certain meanings or qualities.

Let´s consider the astrological paradigm´s links and further implications:
First of all there´s a great closeness to the traditional esoteric systems. Especially alchemy and the Kabballah are using similar symbols; these systems also explicitly refer to the mythical Hermes Trismegistos and his doctrine "as above, so below". To historians this isn´t astonishing at all: both astrology and esoteric thought were integral parts of syncretism; the Mesopotamian astral cult and the gnosis had reached Europe together. The Hellenes succeeded in decisively systematizing the stars´ oracle; yet, in spite of their mental penetration astrology remained a mantic tool - i.e. it still was (and is) a method essentially based on interpretation, depending on some attribution of sense and meaning to the constellations...
(By the way, every thorough examination of the belief in the stars can´t help but extensively honour its long history and tradition; on the other hand, being aware of your origin also is the precondition of knowing who you are - and where to go.)
The esoteric philosophy is based on the idea of the unus mundi - kind of a universal magical reality wherein all objects and beings mysteriously are bound together. To modern (scientific) thought all this seems rather indistinct, dreamlike, not to say childish imagination. That ancient conception could be pretty real, though: only archaic ideas like the unio magica can explain astrology´s laws of cause and effect. We suspect that astrology´s mechanisms of functioning are taking place on quite a "primitive", primordial level of creation - a level, on which body, soul and spirit still are unified; a level, where matter and energy/ consciousness, character and destiny, inside and outside world aren´t differentiated yet. From psychology´s viewpoint this is an area deeply (collectively) unconscious; it´s a reflective or magical-projective level of being - where every (more or less conscious) yearning of the soul immediately is coming true, just like in Bastian´s wonderland Phantasia (M. Ende)...

Ever since it beginnings, astrology intimitately had been interwoven with belief and religion. The teachings from the stars always were embedded in some supernatural cosmology. In ancient times the fixed stars had been equated with the gods; in the Middle Ages people thought angels to live on the planets. Until today in every non-European culture astrology is an integral part of the religious philosophy. There was and still is an (American) Indian, a Taoist, a Hindu, an Islamic, and - last but not least - a specific kind of Christian astrology. Mithraism, Christianity´s alter ego - whom the celebration day of Christmas was stolen from, by the way - truly was an astral religion. Great teachers of the Church, e.g. Thomas Aquino or Luther´s companion Melanchthon taught and believed in astrology; likewise did some bishops and even popes. Ecclesiastical iconography showed Jesus Christ (as regent) amidst the zodiac. Florentine Neo-Platonic Ficino´s philosophical system could be called Christianity´s highest spiritual reconciliation with so-called paganism. Christian Medieval society´s strata were thought to be a copy of the order above. (We may feel the Middle Ages' social conditions pretty miserable and slaverous; yet, in those times people felt safe and sheltered within their cosmos - very much unlike modern man´s rootlessness and restlessness.)
Regarding religion, the astrological conception is going perfectly with man´s belief in some higher being. In dealing with astrology´s phenomena we are almost forced to assume some entity or level beyond - an institution which is directing all the things and processes in the material world. Who else could have invented this complex, breath-taking order encompassing both heaven and earth? Just an instance inconceivable to human mind is capable of co-ordinating this universal, wonderful clockwork of persons, situations and destiny affiliated with each other.

Values also are an essential part of astrology´s paradigm. The importance of values already is implied by the eminent position of "quality" among astrology´s central axioms. "Quality" means that in every round and whole system there is no way of being one-sided; in every comprehensive theory you can´t ignore life´s totality. In a holistic model like astrology every statement to some extent also contains its opposite: a paradox that inevitably is guiding us beyond the visible - towards metaphysical qualities and values.
In the astrologer´s pragmatic daily work value judgments are omnipresent: some aspects and transits are seen rather favorable, others less (in view of the whole). Especially the counselling job is aimed at the individual client´s "best" - according to current time´s contents. For there are many ways to realize analogies: you can "live" a constellation´s content on a so-called higher or lower level, you can live it in a more or less conscious or "redeemed" way.
In the Eastern philosophies of karma and kismet there is no real evolutionary progress. Yet, in astrology - after all a typical product of the occidental mind - we are always trying to improve things; we are always driven to reach some higher evolutionary step. Christian eschatology or the psychology of crucifixion has been teachng us the positive side of problems and difficulties. This attitude has been rooted firmly in our collective unconscious. So, modern psychological astrology in every situation tries to be constructive, too. The astrologer encourages his clients to move towards more consciousness, towards more integration and wholeness. Modern Western astrology is encouraging the individual: go ahead and unfold your unique potential!

Matters of fate and destiny always belonged to the astrologer´s duties. The chart is kind of a short-hand description of the person´s character and endowments. But it is also telling us about the existencial circumstances affiliated; "person = destiny", the formula says. Yet, this "fateful" connection needn´t be seen awful and negative; our "destiny" needn´t be absolutely determining. We aren´t a helpless prey of some monstrous fate; we are the masters of our lives. At least subconsciously we are the directors of the whole scenery going on; we ourselves chose the - necessary but optimal - conditions for us to evolve.

In former times astrology provided the psychological typology most widely accepted. Just remember the Aristotelian doctrine of the elements and temperaments. Or think of the medieval conception of melancholy - which almost was equated with Saturn and his peculiarities. To Paracelsus the soul was an "astral body"; this body´s organs were the planets (similar to the Indian chakras). In between these inner power centres he saw some complex interaction - actors in a play not unlike a modern psychodrama. Nowadays Jungian psychology and the movement of Humanistic Psychology (a.o. gestalt therapy) explicitly refer to that ancient tradition. Contrary to mechanistic psycholgoy (Behaviorism) in their view man is capable of inner development and growth. So-called individuation (i.e. self-realization) is considered the supreme value and ultimate goal of all emotional crises and processes going on.
Astrology´s symbols are very much alike to the unconscious´ products: to modern man both areas are quite "irrational", dazzling, vague and ambiguous. Jung´s term "archetype" - which he empirically distilled out of myths and dreams - can be transferred to the planets and zodiacal signs without any serious theoretical problems. Both the archetypes and astrology´s principles are primordial images; their effect is an impersonal (or rather suprapersonal) and numinous one - especially in the case of the Transsaturnines. Both the archetypes and the astrological symbols can be viewed as unspecific patterns or schemes of acting and feeling. Astrology´s symbols also could be seen as the objective spirit´s (cf. Spranger, Hegel) dimensions or categories - thus giving order to the soul´s world. Last but not least the horoscope is symbolical of the self, i.e. of the whole and complete person. Interestingly, the chart usually is illustrated (drawn) in the shape of a classical mandala: it´s composed of a square (the quadrants) and a circle - an alchemical metaphor promising the substantial possibility of the diverging traits´ synthesis on some higher level...
Humanistic psychologists´ research tools and ways of knowing are akin to astrological counselling, too: usually they are applying qualitative methods (like individual case analyses). And - not to forget - the channels of intuition are extremely important to both therapists and astrologers.

Astrology is not a natural science but a metaphysical one. Whereas the natural sciences are in search of universal laws, the metaphysicual sciences primarily are dealing with things unique and special. Whereas in a natural science´s sterile experimental situation the researcher is seen clearly distant and separate from his object, in the metaphsical sciences´ enquiry the observer can´t help but getting involved personally. The research methods of phenomenology, hermeneutics - and astrology - are trying inwardly to understand a topic´s or person´s essential contents. They want to detect an individual object´s very specific structures of meaning. In these metaphysical sciences the researcher is trying to emotionally find himself in his counterpart; there is no knowing apart from being, there is no knowledge without your personal experience and realisation. In the metaphysical science in order to proceed in understanding your subject you must permit to get touched and moved - especially in regard to your individual failures and defects!
In this sense astrology is more like an art than a science. The chart is similar to a poem, to a piece of music or a painting; the astrological code definitely is not sort of a biochemical or genetic formula. A chart´s symbolism needs our interpretation; its contents need our active mental penetration, some kind of conscious articulation by an "astral artist".

Interpreting symbols is deeply a subjective matter. Every interpretation or counselling depends on the astrologer and the chart´s owner, on the setting and on these factors´ interaction. In astrology´s view time´s quality is permanently changing. Besides, because of the many possible analogies, a constellation´s realisation can´t be foreseen. So, on different spots of time and space the "truth" found by an astrologer may be varying, too; astrological findings quite often can´t be generalized. According to astrology´s paradigmatical presuppositions there is no other way than starting a process of research and interpretation with the biographical - i.e. the individual, subjective - facts at hand. This is the only way to finally reach any objectivity or suprapersonal truth.
Yet, "everything transient is just an image" (Goethe). Perceiving the primordial patterns and structures effective underneath the superficially visible and audible is the interpreting astrologer´s highest duty. Interpretation is a process encircling a specific problem´s or topic´s essence; guided by the analogies and associations arising things successively get clearer. Thus a person´s and situation´s subjective elements can be transcended; by way of patiently and continuously alternating the abstract (symbolic) level with the level of concrete manifestation you are approaching an individual's essence. This is how some deeper, general, "objective" truth of the point in question may come out. This is how in the counselling situation so-called "subjective evidence" is taking place, how the chart´s owner feels "hit" by the astrologer´s interpretation: He feels recognized, understood and supported - because some "higher" instance within (referring to his personal sense and destination) has been touched, because his individual theme has been placed into a greater, more comprehensive, archetypal context.

Astrology has nothing in common with science. The natural and the metaphysical sciences belong to fundamentally different world views. They are diametrally opposed in many respects. They don´t understand each other; they are full of criticism and scepticism regarding the other. Their conceptions of objectivity and truth are totally different - so they´d better stop their futile quarrel. Starting from different points and going towards different ends, the paradigms´ competition doesn´t make any sense.
Yet, in my opinion, science can´t avoid reproaches from outside for being selective and reductive in its proceedings. So its quantitative methods of measuring and testing only can grasp small pieces and single parts of a complex whole. Science is treating living organisms and cyclic processes just like solid and dead materials. The experimental method - which by definition is standardized, i.e. repeatable any time and any place - is failing, if confronted with unique or individual phenomena. Science especially can´t handle empirical data that are interwoven with a qualitative conception of the moment and the numeral figures' quality.
For example, enquiries by means of questionnaires are an inadequate method of testing astrology. This is so, because astrology´s symbols don´t behave "correctly" in a scientific sense: the symbols are complex and interactive, i.e. not linear and unidirectional like ordinary matter´s characteristics. Moreover, they don´t obey classical logic´s commands - they are full of contradictions and opposites. Furthermore, the chart´s owner may live the symbols´ contents actively or passively, he may realize them physically or emotionally - yet, whatever happens still is in - qualitative, analogical - accordance to the primordial principles or archetypes lying underneath. Whatever happens - the symbols´ internal consistence doesn´t get lost; but you can´t put its contents into simple, distinguishable, quantitatively measurable categories of A, B and C!

Because of their quantitative view of numerals, statistics are rather inadequate to test astrology´s truth. Also its primary supposition - of accidental distributions present everywhere - fundamentally is opposed to the astrological conception of the world. After all, every statistic´s starting-point is kind of a chaotic, senseless and Darwinistic universe; ontologically, if you are consequently thinking this to an end, in this world of probabilities there is no room for any finality, i.e. there could be no conscious orientation towards some higher goal (or self).
Another point is: the higher the number of data you collect, i.e. the higher your statistics´ scientific status - the less important the single individual (which is your data´s original source and point of reference!) is seen and appreciated - which is not at all in accordance to astrology's person-centered approach. In statistics all individual particularities systematically are excluded and eliminated; statisticians - euphemistically - call this procedure "neutralisation" or "anonymization". In statistical testing all the things that are unique and special must fall underneath the table - though, in astrology´s view, individuality is the world´s central building-stone...

In the past decades natural science´s paradigm has become visibly shaken. Especially science´s spear-head physics - after having provided for countless civilisatory comforts - have been plucked a lot. Physical science has reached the frontiers of time and space; there its tight causal-mechanistic categories have been overcome. In some experiments of quantum physics the postulated strict separation of subject - the investigator or setting - and the object examined can´t be maintained any longer. - Yet, thus the prevailing paradigm of today's science, which has dominated our thoughts and actions for centuries, is gaining new dimensions: There is room for the ancient concepts of spirit and psyche again - who in fact never could totally be banned from the human sciences (even if technically oriented like modern medicine).
That´s why the phrase paradigm shift now is in everybody´s mouth. Since Kuhn´s days the concept has been generalized and somewhat changed, though. Popular science exaggerated and inflated the term's meaning: in the beginning a "paradigm" had been limited to single sciences like physics; later it became overloaded ideologically and a "paradigm-shift" was equated with some decisive turning-point of the occident´s scientific philosophy in general. Today it´s sort of a slogan and a synonym of the New or Aquarian Age´s dawn; it´s associated with the Western egoistic-materialistic and technological thinking´s decline. Moreover, that hippie idea of a universal revolution is filled with great expectations regarding political, economic and social improvements...

Astrology´s flourishing surely will accompany and support such far-reaching spiritual change. Yet, the stars´ teachings only will be able to play an active role in that process, if they are aware of their specific presuppositions. Astrology shouldn´t unconsciously or even opportunely submit to that seemingly modern - but fundamentally incompatible - paradigm of quantities and causalities. If astrologers strictly keep to their holistic model´s base-lines, they won´t be able to talk of some "astrological factor" (thought to be effective beside heritage, environment, etc.). Measuring the planets´ physical radiations - in order to recognize their "influences" - is an absurd proceeding, anyway.
Those astrologers who aren´t firmly rooted within their paradigm´s ground may run after scientific and social appreciation. But the key for astrology´s revalorization is in academic psychology´s hands. According to Kuhn this comparably "young" science hasn´t formed an own paradigm, yet. By now there is no consensus within the psychological community regarding their objects and standardized methods of research. In order to find such common ground I guess the first thing would be to drop all those statistical testings; psychologists - like astrologers - should liberate themselves from that unnecessary scientific inferiority complex. Academic psychology should accept imaginative theories and integrate conceptions like "archetypes"; the process of "projection" should be examined thorougly, too. Furthermore, acadenic psychologists should no longer arrogantly ignore the soul´s spiritual dimension and its magical aspects. (Badly enough, by now they even can´t define their science´s subject - the soul!) Such advancements in psychology could pave the way for a better understanding and social acceptance of astrology.

* note (1): The concept of every moment bearing specific traits - which are typical of the person or object "born" in that minute - maybe called astrology's fourth basic axiom (this principle also descending from esoteric thought/ from the Hermes Trismegistos' Emerald Table).