Perhaps it is impossible to understand Nietzsche unless one admits that his writings show traces of the disease which very soon prevented his writing at all.  But at the same time, while that is true, there is much more in his work than the ravings of a distempered mind.  There may have been little method, but there was a great deal of genius, in his madness.  While he always overstates his case,—­his colossal egoism leads him to exaggerate any doctrine,—­and while I do not think that the actual doctrines of Nietzsche in the way he puts them will ever gain any general acceptance, while his system of morality may not have any chance of being the moral code of the next generation or even of being regarded as the serious alternative to Christian morality, yet it is not too much to say that he is symptomatic of a new tendency in ethical thought, a tendency of which he is the greatest, if also the most extravagant exponent, but which has its roots in certain new influences which have come to this generation with the ideas and the triumphs, scientific and material, of the preceding generation.

There are two quite different kinds of influence to which the formation of an ethical doctrine may be due.  In the first place, there are the moral sentiments and opinions of the community and of the moralist himself; and, in the second place, there are the scientific and philosophical doctrines accepted by the writer or inspiring what is loosely called the spirit of the time.  In most ethical movements the two kinds of influence will be found co-operating, though the latter is almost entirely absent in some cases.  The incoherence of popular opinions about morality is a potent stimulus to reflexion, and may of itself give rise to systematic ethical enquiry.  This is more particularly the case when a change of social conditions, or contact with alien modes of life, force into light the inadequacy of the conventional morality.  In such a case the new ethical reflexion may have a disintegrating effect upon the traditional code, and give to the movement the character and importance of a revolution.  The reflective activity of the Sophists in ancient Greece—­a movement of the deepest ethical significance—­was in the main of this nature.  It consisted in a radical sifting and criticism of current moral standards, and was due almost entirely to the first class of influences, being affected only in the slightest degree by scientific or philosophical ideas.

Influences of the same kind combine with science and philosophy in moulding the ethical thought of the present day.  Contemporary ethical speculation is by no means exclusively due to the thinkers who attempt to arrive at a consistent interpretation of the nature of reality; and it has features which constantly remind us how closely moral reflexion is connected with the order and changes of social conditions.