As nature abhors a vacuum, so the human being has a dread of his physical emptiness. In certain neurotics this horror vacui occurs, or is expected to occur, following orgasm. Agoston describes this fear, in many examples of abnormal sexual activity, as if it were specifically different from what is generally known as castration fear and its derivatives. Consequently, Agoston—'for the purpose of facilitating free association'—administers benzedrine sulfate to some patients prior to the analytic hour, because he has notice that the drug brings about a feeling of fulness and a corresponding 'sense of security'.