Because of the complex and abstract nature of love, discourse on love is commonly reduced to a thought-terminating cliché, and there are a number of common proverbs regarding love, from Virgil's "Love conquers all" to the Beatles' "All you need is love." Bertrand Russell describes love as a condition of "absolute value," as opposed to relative value. Philosopher Gottfried Leibniz said that love is "to be delighted by the happiness of another.