Page:Essays on the Principles of Human Action (1835).djvu/134

 and the one I have endeavoured to defend is that I suppose the idea of any particular, positive, known good, either relating to ourselves or others to be in itself an efficient motive to action; whereas according to Hartley no idea either of our own interest or that of others has the least tendency to produce any such effect except from association. He infers that there is no essential, original desire of happiness in the human mind, because this desire varies according to circumstances, or is different in different persons, and in the same person at different times according to the humour he is in, &c. This objection indeed holds true if applied to the desire of happiness as a general, indefinite, unknown object; to a necessary, mechanical, uniform disposition in man as a metaphysical agent to the pursuit of good as an abstract essence, without any regard to the manner in which it is impressed on his imagination, to the knowledge which he can possibly have of any object as good, or to his immediate disposition to be affected by it, I have however all along contended that the desire of happiness is natural to the mind only in consequence of the idea, or knowledge of it, in the same manner that it is natural to the eye to see when the object is presented to it; to which it is no objection that this organ is endued with different degrees of sharpness in different persons, or that we sometime see better than at other times. Neither can I conceive how the associated impulses, spoken of in the passage above referred to, without an inherent, independent power in the ideas of certain objects to modify the will, and in the will to influence our actions, can ever in any instance whatever account for voluntary action. I need not attempt to shew that the mechanical impulses to the pursuit of our own good or that of any other person, derived from past associations, cannot be supposed to correspond exactly and uniformly with the