YOUR EYE IS THE LAMP OF YOUR BODY; WHEN YOUR EYE IS SOUND, YOUR WHOLE BODY IS FULL OF LIGHT; BUT WHEN IT IS NOT SOUND, YOUR BODY IS FULL OF DARKNESS. —LUKE 11:34
Look into yourself and examine your reactions to persons and situations, and you will be appalled to discover the prejudiced thinking behind your reactions. It is almost never the concrete reality of this person or thing that you are responding to. You are responding to principles, ideologies, belief systems, economic, political, religious, psychological belief systems; to preconceived ideas and prejudices, whether positive or negative. Take them one at a time, each person and thing and situation and search for your bias separating the reality here before you from your programmed perceptions and your projections. And this exercise will afford you a revelation as divine as any that the Scriptures could provide you with.
Prejudices and beliefs are not the only enemies of clear thinking. There is another pair of enemies called desire and fear. Thinking that is uncontaminated by emotion, namely by desire and fear, and self-interest, calls for an asceticism that is terrifying. People mistakenly assume that their thinking is done by their head; it is done actually by the heart which first dictates the conclusion, then commands the head to provide the reasoning that will defend it. So here is another source of divine revelation. Examine some of the conclusions that you have arrived at and see how they are adulterated by self-interest. This is true of every conclusion, unless you hold it provisionally. Think how tightly you hold on to your conclusions regarding people, for instance. Are those judgments completely free of emotion? If you think they are, you have probably not looked hard enough.
This is the major cause of disagreements and division between nations and individuals. Your interests do not coincide with mine, so your thinking and your conclusions do not agree with mine. How many people do you know whose thinking is at least sometimes opposed to their self-interest? How many times can you recall having engaged in that kind of thinking yourself? How often have you succeeded in placing an impenetrable barrier between the thinking going on in your head and the fears and desires that agitate your heart? Each time you attempt that task you will understand that what clear thinking calls for is not intelligence—that is easily come by—but the courage that has successfully coped with fear and with desire, for the moment you desire something or fear something, your heart will consciously or unconsciously get in the way of your thinking.
This is a consideration for spiritual giants who have come to realize that in order to find truth they need, not doctrinal formulations, but a heart that divests itself of its programming and its self-interest each time that thinking is in progress; a heart that has nothing to protect and owes nothing to ambition and therefore leaves the mind to roam unfettered, fearless and free, in search of truth; a heart that is ever ready to accept new evidence and to change its views. Such a heart then becomes a lamp that enlightens the darkness of the whole body of humanity. If all human beings were fitted with such hearts people would no longer think of themselves as communists or capitalists, as Christians or Muslims or Buddhists. The very clarity of their thinking would show them that all thinking, all concepts, all beliefs are lamps full of darkness, signs of their ignorance. And in that realization the walls of their separate wells would collapse and they would be invaded by the ocean that unites all peoples in the truth.
~From Anthony De Mello, The Way to Love: The Last Meditations of Anthony De Mello