or disagreeable impression of it is also produced anew upon our will. We ourselves, however, do not come back quite unchanged. For with the physical composition of the humours and tension of the nerves, which constantly changes with the hours, days, and years, our mood and point of view also changes. Moreover, the different kinds of ideas which have been there in the meantime have left an echo behind them, the tone of which influences the ideas which follow. Therefore the same thing appears to us at different times, in the morning, in the evening, at mid-day, or on another day, often very different; opposite views of it now press upon each other and increase our doubt. Hence we speak of sleeping upon a matter, and for important determinations we demand a long time for consideration. Now, although this quality of our intellect, as springing from its weakness, has its evident disadvantages, yet, on the other hand, it affords the advantage that after the distraction and the physical change we return to our subject as comparatively new beings, fresh and strange, and thus are able to see it repeatedly in very different lights. From all this it is plain that human consciousness and thought is in its nature necessarily fragmentary, on account of which the theoretical and practical results which are achieved by piecing together such fragments are for the most part defective. In this our thinking consciousness is like a magic lantern, in the focus of which only one picture can appear at a time, and each, even if it represents the noblest objects, must yet soon pass away in order to make room for others of a different, and even most vulgar, description. In practical matters the most important plans and resolutions are formed in general; but others are subordinated to these as means to an end, and others again are subordinated to these, and so on down to the particular case that has to be carried out _in concreto_. They do not, however, come to be carried out in the order of their dignity, but while we are occupied with plans which are great and general, we have to contend with the most trifling details and the cares of the moment. In this way our consciousness becomes still more desultory. In general, theoretical occupations of the mind unfit us for practical affairs, and _vice versâ_.