The three primary types of suffering and the basis upon which they can be overcome: the correct understanding of the Absolute, the Emptiness.
"It is through not understanding, not realizing four things, that I, disciples, as well as you, had to wander so long through this round of rebirths. And what are these four things? They are the Noble Truth of Suffering, the Noble Truth of the Origin of Suffering, the Noble Truth of the Extinction of Suffering, and the Noble Truth of the Path that leads to the extinction of suffering." - Buddha Shakyamuni
The lectures are also playing continuously on Gnostic Radio:
“Gnosis is lived upon facts, withers away in abstractions, and is difficult to find even in the noblest of thoughts.”