27 The explanation of the connection between faith and certainty put forward by the philosopher Ludwig Wittgenstein is well known. For Wittgenstein, believing can be compared to the experience of falling in love: it is something subjective which cannot be proposed as a truth valid for everyone. Indeed, most people nowadays would not consider love as related in any way to truth. Love is seen as an experience associated with the world of fleeting emotions, no longer with truth. But is this an adequate description of love? Love cannot be reduced to an ephemeral emotion. True, it engages our affectivity, but in order to open it to the beloved and thus to blaze a trail leading away from self-centredness and towards another person, in order to build a lasting relationship; love aims at union with the beloved. Here we begin to see how love requires truth. Only to the extent that love is grounded in truth can it endure over time, can it transcend the passing moment and be sufficiently solid to sustain a shared journey. If love is not tied to truth, it falls prey to fickle emotions and cannot stand the test of time. True love, on the other hand, unifies all the elements of our person and becomes a new light pointing the way to a great and fulfilled life. Without truth, love is incapable of establishing a firm bond; it cannot liberate our isolated ego or redeem it from the fleeting moment in order to create life and bear fruit. If love needs truth, truth also needs love. Love and truth are inseparable. Without love, truth becomes cold, impersonal and oppressive for people’s day-to-day lives. The truth we seek, the truth that gives meaning to our journey through life, enlightens us whenever we are touched by love. One who loves realizes that love is an experience of truth, that it opens our eyes to see reality in a new way, in union with the beloved. In this sense, Saint Gregory the Great could write that " amor ipse notitia est ", love is itself a kind of knowledge possessed of its own logic. It is a relational way of viewing the world, which then becomes a form of shared knowledge, vision through the eyes of another and a shared vision of all that exists. William of Saint-Thierry, in the Middle Ages, follows this tradition when he comments on the verse of the Song of Songs where the lover says to the beloved, "Your eyes are doves" ( Song 1:15). The two eyes, says William, are faith-filled reason and love, which then become one in rising to the contemplation of God, when our understanding becomes "an understanding of enlightened love".
Source: Lumen Fidei (Vatican.va)