The fear instinct in its primitive state is anterior to all experiences of danger, pain, and suffering, as is the case in most of the lower animals. In the higher animals where memory is developed, the fear instinct is associated with some form of representation, however vague, and then fear becomes posterior to experience. In man both forms of fear are present. The anterior form is specially found in children, while in adults the posterior form is, under normal conditions, predominating. The primitive anterior type of the fear instinct is by no means absent, in fact, it is more overpowering, its effects are overwhelming when it comes forth from the subconscious regions to which it is confined, and is manifested under conditions of lowered vitality. When the strata of dynamic energies are passed and the strata of reserve energies are reached, the reserve energy not being accessible, the fear instinct is elemental, fundamental, while the fear of pain and of some definite representation of danger, or of suffering is a secondary consequence. People may suffer from pain, disease, and even danger, and still have no fear, while others may have never experienced the pain or disease, and still be obsessed by intense pangs of fear. Fear is _sui generis_, it is at the foundation of animal life. The fear instinct may be awakened directly by a sensory stimulus, when, for instance, one finds himself in darkness and feels some creeping, slimy thing, or when attacked suddenly with a club or a knife. The fear instinct may again be aroused by an expectation, by something to which his dynamic energies cannot respond adequately, while the reserve energies are in abeyance, such for instance as the expectation of some threatening event either to himself or to the objects bound up with his life existence. When one is threatened with some misfortune, with torture, death, or with a mortal disease, or with a serious operation, or when confronted with great danger against which his energies prove inadequate, in such cases the fear is ideational. These types of fear may in turn be either conscious or subconscious. We may thus classify the fears as follows: { Conscious I. Sensory { { Subconscious { Conscious II. Ideational { { Subconscious The fear of the etherized or chloroformed patient is entirely of the subconscious type. It is the arousing of subconscious fear which, from the nature of the case, cannot be reached and alleviated that gives rise to functional psychosis and neurosis. From this standpoint it may be said that _psychopathic diseases are subconscious fear states, in other words functional psychosis or neurosis is essentially a disease of subconscious activities_. This is, in fact, confirmed by my clinical experience and by my psychopathological research work.