Light And Understanding

Et vita erat lux hominum... Hic tangitur quarta conditio, quae est, quod est aliis cognitionem praebens, ideo dicitur lux hominum, quia homines illuminat et videre facit, unde in Psalmo: Signatum est super nos lumen vultus tui, Domine. Sine quo lumine non est videre, sicut dicere Augustinus, quia, sicut non videt oculus, nisi a luce corporali illuminetur; sic non videt intellectus, nisi a luce spiritualissma illustretur. Et licet omnibus cognitionem praebeat, non tamen omnibus praebet cognitionem sui, quia peccatores per ipsam cognoscunt et ipsam non comprehendunt. Ideo dicit: Et lux in tenebris lucet... Cum peccatores facit vera cognoscere; et tenebrae eam non comprehenderunt; quia infidelitatis tenebris obcaecati non cognoscunt; Genesis primo: Tenebrae erant super faciem abyssi, id est infidelitas in facie cordis humani. Unde ad Ephesios quinto: Fuistis aliqunado tenebrae, nunc autem lux in Domino; primae Ioannis primo: Deus lux est, et tenebrae in eo non sunt ullae. Si dixerimus, quoniam societatem habemus cum eo et in tenerbis ambulamus; mentimur et veritatem non facimus. Et per hoc eilditur error ille, qui posuit, omnia esse a fortuna, et non esse providentiam, nec Deum cognoscere acta nostra. Sanctus Boneventura, Commentarius In Evangelium Ioannem, Caput I Source: Here, p513

And the life was the light of men... 1 This touches on the fourth condition, which is, that it is a giving of understanding to others, therefore is it said 'the light of men', because He illuminates men and makes them see, whence in the Psalm: 'The light of your face is sealed on us, O Lord.' 2 Without which light there is no seeing, as Augustine says, 3 because as the eye does not see unless it is illuminated by coporeal light, so the mind does not see unless it is illuminated by that most spiritual light. And He may give cognition to all, but not to all does He give cognition of Himself, because sinners know by it and they do not grasp it. Therefore it is said: And the light shone in darkness... 4 When it makes sinners know truth, 'the darkness did not grasp it', because blinded by the darkness of faithlessness they do not know. In the first book of Genesis it is said: 'Darkness was on the face of the abyss,' 5 which is the faithlessness on the face of the human heart. Whence in the fifth chapter of Ephesians it says: 'You were once in darkness and now you are in the light of the Lord.' 6 The first chapter of the first letter of John says: 'God is light, and there is no darkness in Him. If we say we have association with him and we walk in darkness, we lie and we do not do what is truth.' 7 And by this is removed the error, which says that everything is by chance and there is no providence, and that God does not know our deeds. Saint Bonaventura, Commentary On The Gospel Of Saint John, Chapter 1 1 Jn 1.4 2 Ps 4.7 3 August Soliq 1.8.45 4 Jn 1.5 5 Gen 1.2 6 Ephes 5.8 7 1 Jn 1.5-6