“The lamp of the body is the eye. Therefore, when your eye is good, your whole body also is full of light. But when your eye is bad, your body also is full of darkness. Therefore take heed that the light which is in you is not darkness. If then your whole body is full of light, having no part dark, the whole body will be full of light, as when the bright shining of a lamp gives you light.” Luke 11:34-36 . “It is discernment which in Scripture is described as the eye and the lamp of the body. This is what the Saviour says, ‘your eye is the light of your body, and if your eye is sound then there is light in your whole body. But if your eye is diseased then your entire body will be in darkness’. This eye sees through all the thoughts and actions of a man, examining and illuminating everything which we must do. And if it is not sound in a man, that is, if it is not fortified by good judgment and by well-founded knowledge, if it is deluded by error and by presumption, this makes for darkness in our entire body. The clear thrust of the mind as well as everything we do will be shadowed and we shall be wrapped in the blindness of sin and the blackness of passion. ‘If the light within you is darkness,’ says the Saviour, ‘what a darkness that will be’. For let no one doubt that our thoughts and our works, which originate from the deliberative processes of discernment, will be caught up in the shadows of sin if ever the good judgment of our heart goes astray or is taken over by the night of ignorance.” St John Cassian