There is still greater difficulty in applying this criterion, when we come to the psychological aspect of morality--the aspect most prominent in modern philosophy from the revival of independent ethical speculation till the time of Kant. According to Mr Spencer, "the acts characterised by the more complex motives and the more involved thoughts, have all along been of higher authority for guidance."[240] But the later or more advanced in mental evolution is not always more complex in structure; for it is a characteristic of mental development that the processes by which a result has been arrived at gradually disappear on account of the diminished attention they receive, so that there remains what is, so far as psychical structure is concerned, a simple mental state. Complexity of structure and indirectness of origin are thus really two different characteristics of states of mind, which frequently go together, but frequently part company.[241] When Mr Spencer, accordingly, goes on to say[242] that "for the better preservation of life the primitive simple presentative feelings must be controlled by the later-evolved compound and representative feelings," he is really passing to a different standard without giving up the former. The sympathy with injured Zulus or Afghans which would be approved by Mr Spencer[243] may be a more indirect, representative, or re-representative feeling, than the sentiments which led to British invasion, and, as such, may be more to be commended. But it would be rash to say that sympathy with the "British interests" supposed to be at stake--interests of commerce, and of the balance of political power, as well as those arising from the subtle effect of national prestige--is less complex than the feeling of sympathy with a people dispossessed of its territory. The latter feeling may be more indirect or representative, as implying an imaginative appropriation of the circumstances of another community; but, so far as structure is concerned, it is composed of far fewer and simpler component elements than the feeling for British interests. [Sidenote: neither of which can serve as an ethical standard.]