The commonest and most secure means of reference is {76} the word or name. [1] So confident are we in the “conventional” or artificially adapted character of this mark or sign of reference, that we are inclined to treat it as absolutely unvarying on every occasion of utterance. But of course it is not unvarying. It differs in sound every time it is spoken, and in context and appearance every time we see it in a written shape. Our reliance upon it as identical throughout depends on the fact that it has a recognisable character to which its variations are irrelevant, and which practically crushes out these variations from our attention. Unless we are on the look-out for mispronunciations or misprints, they do not interfere at all with our attention to the main reference of words. We know that it is almost impossible to detect misprints so long as one reads a book with attention to its meaning. This then is a fair parallel to the distinction which we are considering between two kinds of ideas. If the momentary sound or look of a word is analogous to idea as psychical presentation, “the word” as a permanent possession of our knowledge is analogous to the idea as a reference to an object in our systematic world, and is the normal instrument of such a reference. [1] “A name is a sound which has significance according to convention,” _i.e._ according to rational agreement.--_Ar. de Interp_. 16a 19. But either with the word or without it there may be a symbol of another kind. Any psychical image that falls within certain limits may appear as the momentary vehicle of the constant reference to an object. Just as in recognising the reference of a word we omit to notice the accent and loudness with which it is pronounced, or the quality of the paper on which it is printed, just so in recognising the {77} reference of a psychical image our attention fails to note its momentary context, colouring, and detail. If it includes something that definitely belongs to a systematic object in our world of objects, that is enough, unless counteracted by cross references, to effect the suggestion we require, and that, and nothing else, arrests our attention for the moment. When I think of St. Paul’s Cathedral, it may be the west front, or the dome seen from the outside, or the gallery seen from the inside, that happens to occur to my mind; and further, that which does occur to me occurs in a particular form or colouring, dictated by the condition of my memory and attention at the moment. But these peculiarities are dwarfed by the meaning, and unless I consider them for psychological purposes, I do not know that they are there. It is the typical element only, the element which points to the common reference in which my interest centres, that forms the content of the idea in this sense, taken not as a transient feature of the mental complex, but as definitely suggesting a constant object in our constructed world.