Modality
Modality is the way a sign moves, and there are three: cardinal signs begin, fixed signs hold, and mutable signs adapt.
Each modality covers four signs, one from each element, spaced 90 degrees apart. That spacing is why planets in the same modality tend to square or oppose one another, and why a square reads as two planets wanting the same kind of action for different reasons.
It is the second axis of the sign grid, the first being element. Together they identify each sign uniquely: there is exactly one cardinal fire sign, and it is Aries.
Frequently asked
What is the difference between an element and a modality?
An element says what a sign is made of; a modality says how it acts. Every sign has exactly one of each.
What does a fixed-heavy chart suggest?
Endurance and resistance to change, read as a tendency rather than a verdict. The chart ruler's condition matters as much as the count.