Traditional astrology is usually defined as the type of astrology that was practiced in the west prior to the 20th century.
Astrologers in the late 20th and early 21st century often define the type of astrology that they practice as “modern astrology,” seeing it as distinct from the types of astrology that were practiced prior to the modern era. Indeed, the practice of astrology had changed considerably after its revival in the early 20th century, and thus the perception of differences between the ancient and modern traditions is not inaccurate. In the 1980s and 1990s some groups of astrologers began investigating the history of the astrological tradition, and adopting some of the systems and methods that were preserved in older texts from the Hellenistic, Medieval and Renaissance traditions. Some of these astrologers subsequently rejected the practices associated with modern astrology, and attempted to only practice methods that were used in older sources. This further helped to solidify a distinction between “modern” and “traditional” astrology. According to the broadest definition, traditional astrology is simply the type of astrology that was practiced in the west from approximately the 1st century BCE until the 17th century CE, prior to the decline of astrology in western society. Part of the rationale underlying the distinction between traditional and modern astrology is the notion that there was a great deal of continuity in the techniques and the practice of astrology prior to the 18th century, when astrology fell into disrepute in the west. Then during the 18th and 19th centuries there was a break in the tradition. When astrology was revived again in the 20th century, a number of sociological, cosmological and scientific changes led to a wide range of new innovations by astrologers in both the techniques and the conceptualization of astrology. For example, whereas the astrological tradition prior to the 18th century only used the five visible planets and the two luminaries, modern astrology was developed after the outer planets had been discovered, and thus most modern astrologers incorporated them into their practice. Additionally, traditional astrology is often characterized as being more oriented towards studying a person’s fate, and external events in their life, whereas modern astrology is often characterized as being focused primarily on character traits and psychology. These are just two examples of some of the many contrasts that are often made between traditional and modern astrology. To the extent that older astrological practices are quickly becoming adopted by contemporary practitioners, in the future “traditional astrology” may not seem like something that is foreign or distinct, although it will still serve as a useful designation for the traditions of astrology that were practiced prior to the 20th century.