recognize from your own experience the facts which I seek to designate by it.
Now there may be great oscillation in the emotional interest, and the hot places may shift before one almost as rapidly as the sparks that run through burnt-up paper. Then we have the wavering and divided self we heard so much of in the previous lecture. Or the focus of excitement and heat, the point of view from which the aim is taken, may come to lie permanently within a certain system; and then, if the change be a religious one, we call it a conversion, especially if it be by crisis, or sudden.
Let us hereafter, in speaking of the hot place in a man's consciousness, the group of ideas to which he devotes himself, and from which he works, call it the habitual centre of his personal energy. It makes a great difference to a man whether one set of his ideas, or another, be the centre of his energy; and it makes a great difference, as regards any set of ideas which he may possess, whether they become central or remain peripheral in him. To say that a man is 'converted' means, in these terms, that religious ideas, previously peripheral in his consciousness, now take a central place, and that religious aims form the habitual centre of his energy.
Now if you ask of psychology just how the excitement shifts in a man's mental system, and why aims that were peripheral become at a certain moment central, psychology has to reply that although she can give a general description of what happens, she is unable in a given case to account accurately for all the single forces at work. Neither an outside observer nor the Subject who undergoes the process can explain fully how particular experiences are able to change one's centre of energy so decisively, or why they so often have to bide their hour to do so. We have a thought, or we perform an act,
