There is another love of the cross which I have called rational love and which is in the higher part of man, the mind. This love is entirely spiritual; it springs from the knowledge of how happy we can be in suffering for God, and so it can be experienced by the soul, to which it gives interior joy and strength. But although this rational and perceptible joy is good, in fact, excellent, it is not always necessary in order to suffer joyfully for God's sake.
--St. Louis de Montfort, Letter to the Friends of the Cross