This statement will not surprise those who are familiar with hypnotic experimentation, for they know how easy it is to induce sleep in a person who lets himself go, and, on the contrary, how difficult it is in one who resists or who mistrusts the operator. I am persuaded that the impersonal strata of the consciousness play a rôle in psychical phenomena similar to what they play in the phenomena of hypnotism. Therefore, I insist on the necessity for due regard being paid to the medium. I have had much practice, and in all mediums I have met with extreme sensitiveness. Those who have come under the refining influences of education, instruction, or rank, are the most sensitive—‘touchy’; but this sensitiveness ought not to be interpreted as a sign of degeneracy. Certain contemporary savants consider every deviation from the normal state as a blemish! Such a way of thinking implies a veritable _a priori_ judgment, a begging of the question, which is detrimental to the true development of scientific thought. The normal man is only a mean term; there are individuals who are inferior to the mean, there are others who are superior to it. Nature knows not equality. She offers us, everywhere, inequalities, discrepancies, diversities. It is the illusory unity of our own personality, which leads us to unify and to codify natural phenomena and even humanity itself. It is one of the conditions of the organisation of our Sciences, that they become intelligible only on condition of adapting themselves to our particular form of understanding. Nothing authorises our supposing that this form of understanding has any metaphysical reality; it may only be a subjective condition of our perception. It is by an analogous mental process, that we give reality to the intellectual or physical type of the average man. Degeneracy, which is often a sliding backwards, a relapse into inferior types, is a negative deviation from the average man: genius is a positive variation. In the same way, the nervous system of the imaginary average man is but an abstraction; in reality, the sensibility of the nervous system of the different human individualities varies immensely. A negative variation will give beings who are less sensitive, less delicate than those of the average type; a variation in the positive sense will give individuals of a more sensitive and more delicate type. To consider either as abnormal is only grammatically true: the former are _infra_-normal, the latter are _supra_-normal. The first have not reached the average level, the second have passed it. Therefore, it is not astonishing that a more refined sensitivity of the nervous system should have a correspondingly greater emotivity: ‘touchiness’ in itself is a function of emotivity. This seems to me to explain a fact which appears certain—that the feelings of mediums are very easily hurt. A discontented, irritated medium is a bad instrument—as I have had occasion to prove with Eusapia and many other mediums.