It is impossible for man to find that true happiness, which he desires naturally, in any limited good: pleasures, riches, honor, glory, power, knowledge. Our mind, noticing at once the limits of these goods, conceives a higher good and carries us on to desire that higher good. We must repeat: Our will, illumined by our intelligence, has a depth without measure, a depth which only God can fill.
--Reginald Garrigou-Lagrange, Life Everlasting
