To turn now to references, the only mental happenings which are as closely connected with visual words as their tied images are those mysterious events which are usually called thoughts. Thus the arrow symbol in the hieroglyph should perhaps properly be placed near the visual impression of the word. The mere sight of any familiar word is normally followed by a thought of whatever the word may stand for. This thought is sometimes said to be the ‘meaning’, the literal or prose ‘meaning’ of the word. It is wise, however, to avoid the use of ‘meaning’ as a symbol altogether. The terms ‘thought’ and ‘idea’ are less subtle in their ambiguities, and when defined may perhaps be used without confusion. What is essential in thought is its direction or reference to things. What is this direction or reference? How does a thought come to be ‘of’ one thing rather than another? What is the link between a thought and what it is ‘of’? The outline of one answer to these questions has been suggested in Chapter XI. A further account must here be attempted. Without a fairly clear, although, of course, incomplete view, it is impossible to avoid confusion and obscurity in discussing such topics as truth in art, the intellect-_versus_-emotion _imbroglio_, the scope of science, the nature of religion and many others with which criticism must deal. The facts upon which speculations as to the relations between thoughts and the things which they are ‘of’ have been based, have as a rule been taken from introspection. But the facts which introspection yields are notoriously uncertain, and the special position of the observer may well preclude success. Introspection is competent, in some cases, to discover the relations between events which take place within the mind, but cannot by itself give information as to the relations of these events with the external world, and it is precisely this which we are inquiring into when we ask, What connection is there between a thought and that which it is a thought of? For an answer to this question we must look further. There is no doubt that causal relations hold between events in the mind and events outside it. Sometimes these relations are fairly simple. The striking of a clock is the cause of our thinking of its striking. In such a case the external thing is linked with the thought ‘of’ it in a fairly direct fashion, and the view here taken is that to be a thought ‘of’ the striking is to be merely a thought caused in this fashion by the striking. A thought of the striking is nothing else and nothing more than a thought caused by it.