Consequently, it has become evident that the four criteria standards of judgment by which the human mind reaches its conclusions (senses, intellect, traditional or scriptural and inspiration) are faulty and inaccurate. All of them are liable to mistake and error in conclusions. But a statement presented to the mind, accompanied by proofs which the senses can perceive to be correct, which the faculty of reason can accept, which is in accord with traditional authority and sanctioned by the promptings of the heart, can be adjudged and relied upon as perfectly correct, for it has been proved and tested by all the standards of judgment and found to be complete. When we apply but one test, there are possibilities of mistake. This is self-evident and manifest.
(‘Abdu’l-Bahá, Promulgation of Universal Peace, p. 255).
I pray God to lift the veil for thee and to corroborate by the spirit of experience, so that all may be evident to thee, by the Holy Spirit of God.
(‘Abdu’l-Bahá, Tablets of ‘Abdu’l-Bahá v2, p. 478)
The criterion of the senses is not reliable. For instance, consider a mirror and the images reflected in it. These images have no actual corporeal existence. Yet if you had never seen a mirror, you would firmly insist and believe that they were real. The eye sees a mirage upon the desert as a lake of water, but there is no reality in it. As we stand upon the deck of a steamer, the shore appears to be moving, yet we know the land is stationary and we are moving. The earth was believed to be fixed and the sun revolving about it, but although this appears to be so, the reverse is now known to be true. A whirling torch makes a circle of fire appear before the eye, yet we realize there is but one point of light. We behold a shadow moving upon the ground, but it has no material existence, no substance. In deserts the atmospheric effects are particularly productive of illusions which deceive the eye. Once I saw a mirage in which a whole caravan appeared traveling upward into the sky. In the far North other deceptive phenomena appear and baffle human vision. Sometimes three or four suns, called by scientists mock suns, will be shining at the same time, whereas we know that the great solar orb is one and that it remains fixed and single. In brief, the senses are continually deceived, and we are unable to separate that which is reality from that which is not.
(‘Abdu’l-Bahá, The Promulgation of Universal Peace, p. 20)
This is conclusive argument showing that all available human criteria are erroneous and defective … Therefore, man is not justified in saying, “I know because I perceive through my senses,” or “I know because it is proved through my faculty of reason,” or “I know because it is according to tradition and interpretation of the Holy Book,” or “I know because I am inspired.” All human standards of judgment are faulty, finite.
(‘Abdu’l-Bahá, The Promulgation of Universal Peace, p. 22)