"The finer sentiments of the mind, the operations of the understanding, the various agitations and passions, though really in themselves distinct, easily escape us, when surveyed by reflection; nor is it in our power to recall the original object, as often as we have the time to contemplate it. Ambiguity, by this means, is gradually introduced into our reasonings; similar objects are readily taken to be the same: the conclusion becomes at last very wide of the premises."