 When the object of taste is a material object the process by which it becomes pleasurable is more complicated still. The complication is that material objects are not naturally productive of any emotion; they are often naturally productive of simple pleasures and pains, but these are sensations merely. Yet it cannot be doubted that material objects often do produce the complex emotions of beauty and sublimity, and so must also produce the simple emotions that initiate unified trains of ideas of emotion. Hence, material objects, in order to acquire the capacity to produce the complex pleasures of taste, must first acquire the capacity to produce simple emotions. They do so, according to Alison, by coming to signify, through association, qualities of mind that are naturally productive of emotion (Alison 1811, 105–107). These include both active and passive qualities of mind,