This whole deduction is at variance with Spencer's theory that pleasurable excitations are favorable to life, painful ones injurious. And since observation is in direct opposition to his assertion, his followers have been obliged to supplement it with the conception that pain is gradually weeded out by natural selection. On the contrary, we need pain at every instant, since it is the impulse to action; persistence in the same condition through lack of excitation, must result in death; pleasure can never originate action, it can only cause persistence in action already begun. The fact has been too often overlooked, that the motive and the "end" of an action are by no means the same. The motive is pain, and the end is either simply the stilling of pain or an additional positive pleasure. There are, therefore, many actions which are directed to no concrete positive end, but only to the purely negative end of escape from pain without consideration of the further results; a striking example of such action is suicide. Even where positive pleasure appears as an end, it is never in itself the motive to action. In order to become a motive, it must first be transformed into an excitation, into desire for pleasure; and this desire for a definite or an indefinite pleasure is, in its essence, pain--the pain of the absence of pleasure.[60] The pleasure sought may be one already known through experience, or it may be one not yet experienced. In the latter case, the desire is awakened by instruction or reflection, or else induced by instinct. But the motive is always the same, namely, a seeking after pleasure, hence a feeling of pain. This view furnishes us with a psychical explanation of the association of ideas, the mysterious so-called transferrence of the feeling of pleasure from the end to the means. Pleasure begins as soon as we have begun the action which will bring us with certainty to the end desired, and this pleasure may reach such a degree of strength at some point of the process as to conquer the desire for the real end, hem further action, and dispose to continuance at the point reached. The action of the miser may be thus explained.