Every introductory medieval text begins with discussion of the natures of the signs, planets, aspects, and the significations of the houses. Though these basic concepts may be tedious to learn to those who are already versed in some type of astrology, they are immensely important. By diligent study and good command of these basics the student is less likely to err in their judgments and have a more profound understanding of the interconnectedness of the entire astrological system.
The first of these basics is typically the natures of the planets. This teaches the student the basic qualities and natural significations of the planets and how additional significations can be extrapolated from these few core ideas.
Following that are discussions on the qualities of the signs. This introduces students to the signs of the zodiac and their many groupings and descriptions. It gives students an understanding of many of the basic ideas of the energies and natures of each of the signs and gives the students access to many identifying terms to enrich their judgments.
Classical aspect theory is as thought-provoking as it is complex. Sometimes referred to as "configurations" in medieval texts, this discusses what is and is not an aspect and shows us the metrics to use when exposed to new or dissenting ideas. These theories also help the student to identify and describe the different ways in which planets interact with one another.
The significations of the twelve terrestrial houses or places becomes an immensely helpful resource of knowledge when the student begins to advance to other forms of astrology. The ability to assign the matter to the correct house and select the appropriate significator is the deciding factor between an accurate or erroneous judgment.
Finally, the dignities and debilities of the planets give qualitative insight into the significations of the planets by assigning areas of the zodiac they find prosperity or suffering in. Planets give more pleasant experi-ences when they are well placed and are unable to sufficiently provide when they are ill placed.
"...that he who shall learn the nature of the planets and signs without exact judgment of the houses, is like an improvident man, that furnishes himself with a variety of household stuff, having no place wherein to stow them."
- William Lilly, Christian Astrology