z 9 o THE POPULAR SCIENCE MONTHLY, 



doubts arise from some indecision, however momentary, in our action. 

 Sometimes it is not so. I have, for example, to wait in a railway- 

 station, and to pass the time I read the advertisements on the walls, 

 I compare the advantages of different trains and different routes which 

 I never expect to take, merely fancying myself to be in a state of 

 hesitancy, because I am bored with having nothing to trouble me. 

 Feigned hesitancy, whether feigned for mere amusement or with a 

 lofty purpose, plays a great part in the production of scientific in- 

 quiry. However the doubt may originate, it stimulates the mind to 

 an activity which may be slight or energetic, calm or turbulent. 

 Images pass rapidly through consciousness, one incessantly melting 

 into another, until at last, when all is over it may be in a fraction of 

 a second, in an hour, or after long years we find ourselves decided as 

 to how we should act under such circumstances as those which occa- 

 sioned our hesitation. In other words, we have attained belief. 



In this process we observe two sorts of elements of consciousness, 

 the distinction between which may best be made clear by means 

 of an illustration. In a piece of music there are the separate notes, 

 and there is the air. A single tone may be prolonged for an hour 

 or a day, and it exists as perfectly in each second of that time 

 as in the whole taken together; so that, as long as it is sounding, 

 it might be present to a sense from which everything in the past 

 was as completely absent as the future itself. But it is different w r ith 

 the air, the performance of which occupies a certain time, during the 

 portions of which only portions of it are played. It consists in an 

 orderliness in the succession of sounds which strike the ear at differ- 

 ent times ; and to perceive it there must be some continuity of con- 

 sciousness which makes the events of a lapse of time present to us. 

 We certainly only perceive the air by hearing the separate notes; 

 yet we cannot be said to directly hear it, for we hear only what is 

 present at the instant, and an orderliness of succession cannot exist in 

 an instant. These two sorts of objects, what we are immediately 

 conscious of and what we are mediately conscious of, are found in all 

 consciousness. Some elements (the sensations) are completely pres- 

 ent at every instant so long as they last, while others (like thought) 

 are actions having beginning, middle, and end, and consist in a con- 

 gruence in the succession of sensations which flow through the mind. 

 They cannot be immediately present to us, but must cover some por- 

 tion of the past or future. Thought is a thread of melody running 

 through the succession of our sensations. 



We may add that just as a piece of music may bo written in 

 parts, each part having its own air, so various systems of relation- 

 ship of succession subsist together between the same sensations. 

 These different systems are distinguished by having different motives, 

 ideas, or functions. Thought is only one such system, for its sole 

 motive, idea, and function, is to produce belief, and whatever does 



