Why, then, has not the term been introduced before? would not its use have simplified things, have brought the different topics together, have saved a good deal of roundabout phrasing? No doubt. But _there are two dangers in the use of such a technical term_. The one is that you think merely the words themselves, and do not carry your thought back to the nervous system. A determining tendency is an affair not of mind but of body; and if we had used the words from the outset, you might easily have slipped into the belief that there are determining tendencies in the mind, and might thus have left the nervous system out of account. Have you not—to be honest!—thought and spoken of your ‘bodily sensations’ ever since you studied the chapter on sensation? Yet there are no physical or bodily sensations, any more than there are mental determining tendencies; the bodily processes correlated with sensation are not the sensation, and the mental flow correlated with a nervous tendency is not that tendency. The second danger is that you look upon the technical term as self-explanatory; so that, just as popular psychology explains the conduct of the lower animals by ‘instinct,’ without ever asking what instinct is or how it explains, you too explain certain mental phenomena by ‘determining tendency,’ forgetting that the work of correlation is still all to do. New terms bring these risks, that you put the word in place of the facts and confuse a label with an explanation; but they are also inevitable, when new observations accumulate; and this particular term should now be as harmless as it is necessary.