TROPICAL ZODIAC

I didn’t choose Tropical casually. I arrived here through study, lineage, logic, and lived practice.

I use the Tropical Zodiac because of 4 reasons:

Authoritative texts, like Surya Siddhanta and Bhāgavata Purāṇa, speak of the Tropical Zodiac.

All of my teachers who are authoritative astrologers – Ryan Kurczak, Ernst Wilhelm, Vic DiCara – use the Tropical Zodiac.

The 12th divisions, modalities of each sign, and the four elements can be logically explained by the Tropical Zodiac.

In my own practice, the Tropical Zodiac has been flawlessly consistent and accurate.

Before looking at Surya Siddhanta and Bhāgavata Purāṇa, let‘s astronomically explore the structure of the Tropical Zodiac.

The Tropical Zodiac is based on the Sun‘s movement through space relative to the Earth. The beginning point of the Zodiac is accepted to be where the Sun is exactly centred over the Earth‘s equator on its journey towards the North. This is also commonly known as the Vernal Equinox point.

The word „Tropical“ stems from the Ancient Greek „tropikos, “ which translates as „to turn, to change direction.“

As the Sun moves through space relative to Earth, it constantly changes directions, as it travels from the East to the most Northern point (Tropical Cancer) and marks Summer Solstice, then moves towards the West marking autumn Vernal Equinox (Tropical Libra), then descends to the most Southern point (Tropical Capricorn), where winter solstice occurs, and then returns back to the East (Tropical Aries) to mark Spring Vernal Equinox.

From Chapter 14
bhacakra-nābhau viṣuvad dvitīyam samasūtragaṃ
ayana dvitayan caiva catasraḥ prathitāstutaḥ
tad antaresu saṅkrānti dvitayam dvitayam punaḥ
bhānor makara saṅkrānteḥ ṣaṇmāsā uttarāyaṇam
karkādeś tu tathā vasyāt ṣaṇmāsā dakṣiṇāyanam
meṣādyo dvādaśaite māsāstair eva vatsaraḥ

Translated by Vic DiCara:
The two solstices and equinoxes are the thread upon which the core of the zodiac exists. Two borders are between each point. It takes the Sun six months to reach the northern solstice after entering Capricorn; and six months to reach the southern solstice after entering Cancer.
The twelve divisions beginning from Aries are certainly the months which constitute a year.

Here, the zodiac is clearly defined through equinoxes, solstices, and solar months.

From Division 5, Chapter 21
sa eṣa udagayana-dakṣiṇāyana-vaiṣuvata-saṁjñābhir māndya-
śaighrya-samānābhir gatibhir
ārohaṇāvarohaṇa-samāna-sthāneṣu yatha-savanam
abhipadyamāno
makarādiṣu rāśiṣv aho-rātrāṇi dīrgha-hrasva-samānāni
vidhatte
yadā meṣa-tulayor vartate tadāho-rātrāṇi samānāni bhavanti

Translated by Vic DiCara:
The Sun moves at varying speed between the northern solstice, southern solstice, and equinoctial points. Its rise towards the northern solstice, its fall towards the southern solstice, and its crossing the middle point can be known by measuring the days.
The days and nights grow longer and shorter, revealing which of the signs — Capricorn, etc. — the Sun is in. When the Sun is in Aries and Libra, the days and nights are equal.

Here, the zodiac is also clearly defined through equinoxes, solstices, and solar months.

All of the Zodiac signs belong to one of the four elements.
The Tropical system allows for a logical explanation of how and why:

The East is where the Sun rises, thus it is related to the Fire element (Aries) – taking the lead to initiate a new beginning.
The West is where the Sun sets, thus it is related to the Air element (Libra) – after the day we rest, relax, and have fun.
The South is the Earth element (Capricorn) since it is at the bottom. Earth provides us with stability.
The North is the sky, above our heads, inclining us to contemplate life deeply: what’s out there, what is the Universe, and who am I in the greater scheme of existence? That’s the Water element (Cancer).

All of the Zodiac signs belong to one of the 3 modalities (cardinal, fixed, dual).
There is a logical way to explain what grants each sign its modality when using the Tropical system:

The Sun crossing one of the 4 directions opens a new quadrant of the sky, and thus all of the 4 Zodiac signs related to the 4 directions (Aries, Cancer, Libra, Capricorn) have a cardinal modality; cardinal meaning “of great importance, leading, opening doors”.
Then, in the next sign (Taurus, Leo, Scorpio, Aquarius), the Sun keeps moving in the same direction, thus granting a fixed modality.
In the third sign (Gemini, Virgo, Sagittarius, Pisces), the Sun is in a plural position, staying in the same quadrant, while simultaneously moving into a new one; thus, these signs are dual.