Don’t Judge – Astrology’s Scientific Past and Present

by Lindsey T. Thurston

Graphic design by Emily Tjan

“A physician without knowledge of astrology has no right to call himself a physician”

The namesake of the modern physicians’ Hippocratic Oath has been attributed to this quotation, which may elicit surprise from steadfast scientists and critics of the newspaper horoscope.1 Astrological medicine was once part of a physician’s university training,2 but surely modern medicine doesn’t require a deep understanding of zodiac signs and the lunar cycle?

Astrology has observed connections between celestial and terrestrial events for millennia. This practice relied on planetary orbits around the sun, lunar cycles, and constellations to better understand human behaviour, and most importantly, humans’ interactions with the Earth. We can consider two streams of astrology: natural and judicial.2 

Natural astrology was based on astronomy, the science of the stars, where patterns of past events were used to predict future terrestrial events. For example, mapping the lunar cycle informed early human civilizations of the moon’s influence on the tide and led to the origin of the calendar. Tracking constellations provided the first tool for navigating the changing seasons as they rise in the night sky in a particular sequence with the Earth’s solar orbit. Constellations were used to predict annual flooding and optimal crop growth. Today, we see evidence of sophisticated astrological mapping in the placement of ancient temples that align with certain celestial cycles.3

On the other hand, judicial astrology applied more to individual health and personal matters. Judicial astrology was used in medicine for centuries and gives rise to the astrological signs we’re familiar with today.2  

What’s Your Sign?

The constellations: Aries, Taurus, Gemini, Cancer, Leo, Virgo, Libra, Scorpio, Sagittarius, Capricorn, Aquarius, and Pisces make up the Western zodiac signs. Most of us understand astrology as the constellation that appears in the sky on our birthday and the quizzical hold it has on our personality and behaviour. But this is only one part of the horoscope or astrological birth chart. 

The birth chart maps the entire sky at the time of birth and astrologers believe the culmination of celestial placements creates individual identities and personalities. The three major elements that make up the birth chart are the sun, moon, and rising signs. The aptly named sun sign captures the point of the Earth’s rotation around the sun at the time of birth. The sun sign is commonly referenced when asked, “what’s your sign?” The moon sign refers to the position of the moon, and the rising sign to the constellation that was rising on the Eastern horizon at the time of birth. Birth charts differ from individual to individual based on the geographical location and the time of birth, right down to the minute. 

Not Just a Gimmick

The validity of astrologically influenced human behaviour has long been criticized. Reading a daily horoscope can be a fun gag or even thought-provoking, but these philosophical proclamations sway far from the sophisticated origins of natural astrology. 

In fact, some scientific studies have falsified the relationship between astrological signs and specific human behaviour, reporting that astrology performs no better than chance.5 Another study demonstrated that the belief in astrology can be influenced by confirmation bias, or the tendency to only seek out and interpret information that confirms a belief.6 Still, astrological medicine may have predicted the biological correlations more recently demonstrated between birthdate and the risk of some diseases.1

Modern astrology is considered a pseudoscience, but does this render it completely useless? For some, astrology still serves a purpose beyond the newspaper horoscope. In the US, the psychic services market, including astrology, was valued at $2.2 billion in 2021.7 Astrological practices are part of the post-pandemic wellness movement, which prioritizes mind, body, soul, and spirit.8 Astrology offers an opportunity for introspection, to explore spirituality, and to confront personal obstacles.9 In this way, followers of astrology are not necessarily turning to the sky for answers to their problems, but rather using the stars to develop a deeper understanding of the self and to attain a sense of non-religious spirituality. The application of modern astrology, thus, falls to the individual and their interpretations. 

It is easy to pass judgement on the seemingly frivolous and unscientific pastime of astrology. However, our society is ripe with frivolous and unscientific ventures. Whether you turn to the stars to calm your anxieties or to learn of a change in season, there may be power in believing. Afterall, participating in spiritual practice has been correlated with better mental and physical health.10 So, what’s your sign?