Do not believe anything (simply) because you have heard it.
Do not believe in traditions because they have been handed down for many generations.
Do not believe in anything because it is spoken and rumored by many.
Do not believe in anything (simply) because it is in your religious books.
Do not believe in anything merely on the authority of your teachers and elders.
But after observation and analysis, when you find that anything agrees with reason and is conductive to the good of and benefit of one and all then accept it and live up to it.
– Gautama Buddha, Anguttara Nikaya vol I
“Esoteric Buddhism teaches that Reality presents two aspects, one relative finite and conditioned, and one absolute, infinite and unconditioned. Seen with the eye of the unenlightenend being who is turned about on the wheel of existence these two aspects appear separate and irreconcilable, but to the Eye of the Buddha (butsugen) at the unmoving hub they are the inseperable facts of a single truth. In the partial view from the periphery all things are seen as transient and in momentary transformation, lacking an abiding self-nature; but in his total, all-encompasing view from the centre a Buddha sees that the imperfect, ephemeral and mutable dharmas merge with perfect, eternal and immutable Suchness (tathata, shinnyo). He sees that the world of fleeting, impermanent forms and the Buddha’s world of adamantine durability are non-dual.” – The Matrix and Diamond World Mandalas of Shingon Buddhism (Adrian Snodgrass)