The mind is a control mechanism in so far as what utility is for it is not simply a nourishing substance called happiness but a feeling of power or potency in relation to that large realm of matters in which it contributes only a fraction of the operative causes and a larger fraction, to its own perspective, of the effects. If there is a world in which the mind feels more or less sovereign there is also a world, more vital to its health, in which it finds a play of forces which influence its continued well-being, or are strongly believed to do so, and over which it has only a vague or indirect sway, and towards which its attitude must veer towards the propitiatory or the fantastic. This second world, no matter how much we might believe we have tamed it, is the world of anxiety, since lying on its horizon are the events we conceive of as decisive changes or destructions of our destiny - destiny itself, an inexorable causality affecting us from the outside, being a notion arising only in this world. If the dividing line between these worlds were kept clearly marked, with consolidation and stagnation on one side and conjugation and destruction on the other that would be fine, but like political parties that have long been rivals, their relations are marked by appropriations, defections, betrayals, denials, impersonations and falsifications.