Writing 1,300 years before Aquinas, the Roman Stoic Seneca claims in a letter that hope is not a virtue and actually detrimental to our moral state. Stoics believed that all virtue should lead to tranquility of mind. Seneca argues that far from bringing tranquility, hope leads us into fear about our future state. He writes,
"Beasts avoid dangers they can see, and once they have escaped them are free from care; but we humans torment ourselves over what will happen as well as what has happened. Many of our blessings bring trouble to us; for memory recalls the tortures of fear, while foresight anticipates them. The present alone can make no man wretched"
Letters V.9
Solomon also seems to present hope as a double-edged sword, with the proverb:
Hope deferred maketh the heart sick:
but when the desire cometh, it is a tree of life.
Proverbs 13:12
So how is hope a virtue? The question may be clarified with another question, "What are we hoping for?" If our hope revolves around comfort, it will indeed lead us to paralyzing fear. This is why Jesus says, "Take no thought for your life, saying What shall we eat? or, What shall we drink? or, Wherewithal shall we be clothed?" (Matt. 6:25). True hope is free of anxiety.
And so Aquinas was very careful to address this question in his discussion on hope. Remember that his definition of the object of hope is "a future good that is difficult, but possible, to attain." Aquinas follows this with two further explanatory statements. First, the object of hope really includes both the future good and the needed divine assistance to achieve the future good; and second, God is not merely the means to achieve what we hope for, but truly what we hope for. In other words, all future good and happiness comes from God. And thus, placing our hope in other people or things as the primary cause and goal of happiness is, according to Aquinas, counter to the virtue of hope.
Aquinas was drawing on a rich scriptural tradition for this definition of hope. For example, the psalmist David repeatedly sings, "I waited patiently for the Lord." This hope led him to act confidently and brought him through trials. Hope leads us to act not out of fear, but out of confidence that there is a point to acting in the present. C.S. Lewis writes in Mere Christianity,
“Hope...means a continual looking forward to the eternal world that is not (as some modern people think) a form of escapism or wishful thinking, but one of the things a Christian is meant to do. It does not mean that we are to leave the present world as it is. If you read history, you will find that the Christians who did most for the present world were just those who thought most of the next."
One of my favorite stories on hope is the movie Shawshank Redemption. Andy Dufrene has been unjustly accused of murder and given life in Shawshank prison. At the beginning of his time there, a long-term inmate, Red, says to him, “Let me tell you something my friend. Hope is a dangerous thing. Hope can drive a man insane.” In other words, hope as mere longing for something good to happen will make the heart sick. However, hope for justice--for freedom from unjust treatment and imprisonment--is what Andy clings to for three decades of incarcerated misery. It drives him to act heroically and decisively. In the end, as a free man, he writes, "Hope is a good thing, maybe the best of things, and no good thing ever dies."