For those of weaker minds the omniscient Buddha taught, to accord with the predispositions of those to be trained, that the object of knowledge have real existence; but from the perspective of higher truth, nothing from a Hindering Spirit to a Buddha has real existence. There are no meditators, no objects of meditation, no spiritual progress, no path with signs, no resultant kayas, no wisdom, and therefore no nirvana.

-- Milarepa