Feast of St Eusebius, Bishop of Samosata
IT IS UPON us who continue in this quiet and peaceful course of life that the truth will shine, illuminating the eyes of our soul with its own rays. This truth, which was then manifested by the ineffable and mysterious illumination which came to Moses, is God.
And if the flame by which the soul of the prophet was illuminated was kindled from a thorny bush, even this fact will not be useless for our inquiry. For if truth is God and truth is light—the Gospel testified by these sublime and divine names to the God who made Himself visible to us in the flesh—such guidance of virtue leads us to know that light which has reached down even to human nature. Lest one think that the radiance did not come from a material substance, this light did not shine from some luminary among the stars but came from an earthly bush and surpassed the heavenly luminaries in brilliance.
From this we may learn also the mystery of the Virgin: The light of divinity which through birth shone from her into human life did not consume the burning bush, even as the flower of her virginity was not withered by giving birth.
That light teaches us what we must do to stand within the rays of the true light: Sandaled feet cannot ascend that height where the light of truth is seen, but the dead and earthly covering of skins, which was placed around our nature at the beginning when we were found naked because of disobedience to the divine will, must be removed from the feet of the soul. When we do this, the knowledge of the truth will result and manifest itself. The full knowledge of being comes about by purifying our opinion concerning nonbeing.
In my view the definition of truth is this: not to have a mistaken apprehension of Being. Falsehood is a kind of impression which arises in the understanding about nonbeing: as though what does not exist does, in fact, exist. But truth is the sure apprehension of real Being. So, whoever applies himself in quietness to higher philosophical matters over a long period of time will barely apprehend what true Being is, that is, what possesses existence in its own nature, and what nonbeing is, that is, what is existence only in appearance, with no self-subsisting nature.
It seems to me that at the time the great Moses was instructed in the theophany he came to know that none of those things which are apprehended by sense perception and contemplated by the understanding really subsists, but that the transcendent essence and cause of the universe, on which everything depends, alone subsists.
For even if the understanding looks upon any other existing things, reason observes in absolutely none of them the self-sufficiency by which they could exist without participating in true Being. On the other hand, that which is always the same, neither increasing nor diminishing, immutable to all change whether to better or to worse (for it is far removed from the inferior and it has no superior), standing in need of nothing else, alone desirable, participated in by all but not lessened by their participation—this is truly real Being. And the apprehension of it is the knowledge of truth.
In the same way that Moses on that occasion attained to this knowledge, so now does everyone who, like him, divests himself of the earthly covering and looks to the light shining from the bramble bush, that is, to the Radiance which shines upon us through this thorny flesh and which is (as the Gospel says) the true light and the truth itself. A person like this becomes able to help others to salvation, to destroy the tyranny which holds power wickedly, and to deliver to freedom everyone held in evil servitude.
—St Gregory of Nyssa, The Life of Moses