The careful consideration of psychic factors is of importance in restoring not merely the individual's balance, but society's as well; otherwise the destructive tendencies easily gain the upper hand. For the psychic economy, to appeal to paranoia is to invest capital in wild speculation. The intermingling of politico-cultural paranoias in the twentieth century is increasingly attributable to the spread of the mass media, which, while bringing more truths to more people, facilitated the spread of 'collective psychic infections'. In modern society, communication is channelled into the mass media and filtered through the institutions which preside over them. Paranoia, in a diluted form, is bought and sold every day, in the street, not in psychiatric institutions. The real individual forms of delusional paranoia are rarer than other psychiatric illnesses. Their frequency is generally considered to be less than 0.03 per cent.