"Reality is incapable of illusion"
This is a follow up on the previous maxim. It simply says that reality can't lie, even though we insist it does – say, in the form of an illusion.
When we discover that something isn't what we took it to be, and the consequences are benign or entertaining, we think something like "reality just tricked me." But if the deception has any negative effects, if we don't like the surprising new truth, which is undeniably more real than our earlier impression, we insist "reality lied to me!"
But think about this. Reality, to be real, must be real. All of it – no exceptions. Reality can't be anything other than what it actually is. Simply put, an actual unreality is impossible.
Therefore an illusion, deception, mirage, chimera, trickery, etc. is actually just a mistaken impression that exists in our mind, having already decided what something is supposed to be.
And the only reliable context available to us to clear up our misapprehensions? Reality of course.