If one considers how much reason every person has for anxiety and timid self-concealment, and how three-quarters of his energy and goodwill can be paralyzed and made unfruitful by it, one has to be very grateful to fashion, insofar as it sets that three-quarters free and communicates self-confidence and mutual cheerful agreeableness to those who know they are subject to its law.
— Friedrich Nietzsche

The traditional disputes of philosophers are, for the most part, as unwarranted as they are unfruitful.
— Sir Alfred Jules Ayer

Reason now gazes above the realm of the dark but warm feelings as the Alpine peaks do above the clouds. They behold the sun more clearly and distinctly, but they are cold and unfruitful.
— G. C. (Georg Christoph) Lichtenberg

A beginner must look on himself as one setting out to make a garden for his Lord's pleasure, on most unfruitful soil which abounds in weeds. His Majesty roots up the weeds and will put in good plants instead. Let us reckon that this is already done when the soul decides to practice prayer and has begun to do so.
— Saint Teresa of Avila