Beauty is an objective earthly reality that points to God
Whether we are discussing the newest orchestral hall downtown, the attractiveness of a member of the opposite sex or a painting on the wall, everyone has different tastes. Yet tastes are not what defines beauty (though certainly we can recognize and appreciate different aspects of beautiful things), because beauty is an objective earthly reality that is a sign of God's goodness.
St. Thomas Aquinas tells us that “Beauty is that which when perceived, pleases.” This is not a full definition of beauty as such, but instead tells us that beauty is not just a descriptive adjective; it is a reality that can be perceived. Aquinas's description also teaches us that beauty is something that we are able to glimpse, whether that be through sight, hearing or touch.
We know that everything that is good has been created by God. Through the beauty of Creation, we learn more about our Creator, who is beauty itself. The Catechism tells us that God communicates to us through beauty: “God reveals himself to him through the universal language of creation, the work of his Word, of his wisdom: the order and harmony of the cosmos – which both the child and the scientist discover – “from the greatness and beauty of created things comes a corresponding perception of their Creator … for the author of beauty created them” (2500).
Of course, beauty can be found not only in God’s creation, but also in man-made art. What makes art of any form beautiful is that it conveys some truth about man’s relationship with God, about creation, or about God himself. This is not to say that all beautiful art must be sacred art, but rather that it is a vehicle through which truth is conveyed. For more on what makes art and sacred art in particular beautiful, read Catechism articles 2501 and 2502.
Human persons can perceive truth (God being the fullness thereof) through manifestations of beauty – in nature, in man-made creations and in art. The poet John Keats famously wrote, “‘Beauty is truth, truth beauty,’ – that is all / Ye know on earth, and all ye need to know.” Beauty may not be all we need to know, but it certainly is a sign that points us toward the beauty and truth of our Creator.