If depression is the disease of the 21st century, happiness is the fashionable topic and the most desired by today's society. This is one of the reasons why happiness has become a lucrative business, so much so that today more than in other times there are various institutions that offer techniques, therapies and modalities to be happy. And in a world so relativistic, subjectivist, sentimentalist and that turns its back on the reality of things to see as real something put together in the mind of man himself, and that brings as a consequence the disturbance of the soul, which is reflected in diseases such as stress, anxiety, existential emptiness and depression, so it is very necessary to turn our eyes to St. Augustine and St. Thomas Aquinas, whose doctrine offers us the neat way to the top where lies the true, possible and real happiness.