Sec. 10. This superiority of specific expressions is clearly due to a saving of the effort required to translate words into thoughts. As we do not think in generals but in particulars--as, whenever any class of things is referred to, we represent it to ourselves by calling to mind individual members of it; it follows that when an abstract word is used, the bearer or reader has to choose from his stock of images, one or more, by which he may figure to himself the genus mentioned. In doing this, some delay must arise some force be expended; and if, by employing a specific term, an appropriate image can be at once suggested, an economy is achieved, and a more vivid impression produced. iii. The Principle of Economy applied to Sentences. Sec. 11. Turning now from the choice of words to their sequence, we shall find the same general principle hold good. We have _a priori_ reasons for believing that in every sentence there is some one order of words more effective than any other; and that this order is the one which presents the elements of the proposition in the succession in which they may be most readily put together. As in a narrative, the events should be stated in such sequence that the mind may not have to go backwards and forwards in order to rightly connect them; as in a group of sentences, the arrangement should be such, that each of them may be understood as it comes, without waiting for subsequent ones; so in every sentence, the sequence of words should be that which suggests the constituents of the thought in the order most convenient for the building up that thought. Duly to enforce this truth, and to prepare the way for applications of it, we must briefly inquire into the mental act by which the meaning of a series of words is apprehended.