Tenet #1: Duality Dies at Dawn!

Final Crisis: Superman Beyond 2 (Morrison, Mahnke)

The scriptures often remind us that the Joker is a dark mirror of the Batman, always playing the role of allegorical opposition.  Their relationship is an expression of the dual forces in the universe.  Order and chaos, death and life, good and evil:

Batman 680 (Morrison, Daniel)

But we also find that, being opposites, one cannot exist without the other.  In Hunting the Dark Knight, Dr. Will Brooker states, "As counterpoints and contrasts, the villains are locked into a ritualized dance with Batman; on one level, he justifies their existence, and they justify his, just as each medieval carnival was linked to a sacred feast.  Without Batman, the villains would have no challenge, no real raison d'être, and the reverse is also true; the two sides, particularly the love-hate pairing of Batman and Joker, define and, in a sense, create each other."

Or, as the Joker himself says in Nolan's The Dark Knight, "You complete me."

Batman 663 (Morrison, Van Fleet)

In Alan Moore's The Killing Joke, we find the doctrine of 'The One Bad Day.'  It illustrates the notion that the only difference between the Clown Prince of Crime and the Caped Crusader is a matter of perspective.

Batman: The Killing Joke (Moore, Bolland)

The Bat myth explores the idea that seeming opposites are, in reality, halves of a whole.

Much like Ramakrishna's vision of Kali giving birth to the universe and then devouring it, the ongoing battle between the Batman and the Joker, when seen from a human vantage, gives us a cyclical view of reality; but when seen from a higher temporal  perspective (i.e. one where all times are simultaneous), a cycle becomes a solid object.  Ebb and flow become literal parts of a whole.

Or we can look at a thermometer (which is probably less annoying than trying to imagine what events look like when space-time is viewed as an object instead of a process).  On one end is 'hot'.  On the other is 'cold'.  But where in the middle does one become the other?

An object's 'coldness' or 'hotness' is not an intrinsic quality, but depends on the subjective judgement of a viewer.  Hot and cold may be opposites, but they're on the same thermometer.

The Batman teaches us that there are no dualities.  Rather than being a force of Good, he is a force of Justice.  Justice is blind, holding the scales of Libra in one hand, and the sword of reason in the other.  In Crowley's Thoth Tarot deck, 'Justice' is renamed 'Adjustment', and is defined by Crowley as "balance against each thought. it's exact opposite. For the marriage of these is the annihilation of illusion".  It isn't about good over evil or positive over negative. It's about balance between contradictions.

Justice isn't always aimed at the negative aspects of the universe, either.  The Batman is a counterweight to all the denizens of Gotham, not just the villains.  Think of the driven, cold, and calculating role he holds in contrast to the intuitive, empathic, and compassionate Dick Grayson.  Or the self-centered, self-destructive Bruce Wayne in balance with the reasonable and responsible Alfred Pennyworth.

In all things, the Batman is a call to balance, leading us to question the absolutes we take for granted.  And by revealing that duality has no reality outside of our perception, he has perhaps laid stake to the old mystical claim that everything is, in fact, one.