One, who is really anxious to do his duty, must be very weak, if he can imagine that he has much occasion for them; and with regard to one who is negligent of it, the style of those writings is not such as is likely to awaken him to more attention. None of them tend to animate us to what is generous and noble. None of them tend to soften us to what is gentle and humane.
 Adam Smith, The Theory of Moral Sentiments (1759). copy citation

Context

“because, notwithstanding the multitude of cases collected in them, yet upon account of the still greater variety of possible circumstances, it is a chance, if among all those cases there be found one exactly parallel to that under consideration. One, who is really anxious to do his duty, must be very weak, if he can imagine that he has much occasion for them; and with regard to one who is negligent of it, the style of those writings is not such as is likely to awaken him to more attention. None of them tend to animate us to what is generous and noble. None of them tend to soften us to what is gentle and humane. Many of them, on the contrary, tend rather to teach us to chicane with our own consciences, and by their vain subtilties serve to authorise innumerable evasive refinements with regard to the most essential articles of our duty.” source