Let us here parenthetically notice that the physiological tendency in the nervous system is an evolved complication and a specialized development of one of the fundamental properties of protoplasm--that which is often spoken of as irritability. One of the characteristics of all living matter is its “explosive” instability. So that at the very threshold of organic behaviour we have the analogue of that which, in its developed form, becomes the tendency of the nervous system to discharge as the result of stimulation. The conative tendency of the psychologist, therefore, has its roots deep down in the elemental germs of all organic life. And this conative tendency is, says Dr. Stout, not only a fact but an experience. Let us return to our hungry chick that pecks at a grain of corn. And let us grant that as the result of stimulation there arise states of consciousness which we describe as a feeling of hunger and the sight of the grain of corn. The nervous system now discharges; and there are introduced into the situation a further group of data, the motor consciousness of the actual behaviour, sensory data from the results of the act, the seizing of the grain and so forth. The situation has unquestionably changed. But is there any specific consciousness of the conative tendency as such? Is there any “peculiar mode of being conscious which constitutes the experience which is called conation”? It is difficult to say. Hence we find differences of opinion among psychologists as to what, from the psychological point of view, the impulse actually is. Is it simply the conscious situation prior to the response? Is it a feeling of the change from the initial to the succeeding phase? Or are new data introduced apart from those afforded by stimulation on the one hand and response on the other? We will not attempt to decide. Without determining its exact nature we may rest content with the very general statement that impulse is a concomitant of a change in the conscious situation.