I had never heard of the Apollonian - Dionysian dichotomy until the Promethean Antagonist had mentioned it to me a few months ago. Though it is a centuries-old concept and is central to the works of major philosophers from the mid-19th century onward, it is almost nowhere to be found in mainstream culture.
The idea is that we can separate human drives into two modalitites:
Apollonian: logical, civilized, disciplined. Associated with the Sun.
Dionysian: irrational, emotional, chaotic. Arguably connected with Pluto and/or Neptune.
Libertarians familiar with the underpinnings of their own political philosophy may recognize that libertarianism is deeply Apollonian. Libertarianism at its core is based on rationality and non-aggression (reflecting a predilection for solving problems through dialogue and consensus rather than by force). The statist impulse is one of Dionysian irrationality: the sword before the pen and the battlefield before the negotiating table. Ayn Rand's Atlas Shrugged can be said to depict a version of this dichotomy, fusing it directly with the libertarian-authoritarian spectrum.
When we include the astrological Pallas in the mix, and peruse the thousands of examples of natal and event charts on this blog and associated web site, we can see that the Apollonian - Dionysian dichotomy is all about astrology. Literally, and directly. I believe that Nietzsche, Freud, Rand, Paglia, and others when discussing this dichotomy were actually discussing the astrological Pallas in different configurations. We can express the dichotomy thus:
Apollonian: Pallas (or ruler) with Sun, Mercury, and/or North Node.
Dionysian: Pallas (or ruler) with Pluto, discordant aspect from Jupiter, and/or with South Node.
Apollonian aspects and transits give us Apollonian traits and actions. Libertarians and liberty, peacemakers and peace treaties. These things are effects of the "Apollonian" traits of favoring logic over emotion and impulse control over surrender to the id.
Dionysian aspects and transits give us Dionysian traits and actions. Statism, stupidity, war, killings, rape, and those who perpetrate such things. These are effects of the "Dionysian" tendency to surrender to emotion and favor action over full logical consideration.
Again, I refer to the thousands of examples in my online materials including this blog. The correspondences between the astrological aspects and the sides of the dichotomy are so strong (not merely "statistically significant" but near-total) that one might well take them as "proof" that astrology itself is valid.
In past, I've used different terms to describe the astrology of the Pallas spectrum (and the Apollonian - Dionysian dichotomy). I've described "Apollonian" Pallas aspects as "libertarian" or "defensive" and "Dionysian" aspects as "authoritarian" or "aggressive" for years. In the future, I'll try to use "Apollonian" and "Dionysian" so as to better relate my work to the rich existing body of Western philosophy.