Psychosis takes many forms. You can be psychotic about everything or you can concentrate on one particular topic. Bill represented ubiquitous dementia; madness had infiltrated every part of his life, or so I presume. The fixed idea kind of madness is fascinating, if you are inclined toward viewing with interest something that is palpably impossible and yet nonetheless exists. Over-valence is a notion about possibilities in the human mind, possibilities of something going wrong, that did it not exist it could not be supposed. I mean by this simply that you have to see an over-valent idea at work fully to appreciate it. The older term is idée fixe. Over-valent idea expresses it better, because this is a term derived from mechanics and chemistry and biology; it is a graphic term and it involves the notion of power. The essence of valence is power and that is what I am talking about; I speak of an idea that once it comes into the human mind, the mind, I mean, of a given human being, it not only never goes away, it also consumes everything else in the mind so that, finally, the person is gone, the mind as such is gone, and only the over-valent idea remains. How does such a thing begin? When does it begin? Jung speaks somewhere-I forget which of his books it is mentioned in-but anyhow he speaks in one place of a person, a normal person, into whose mind one day a certain idea comes, and that idea never goes away. Moreover, Jung says, upon the entering of that idea into the person's mind, nothing new ever happens to that mind or in that mind; time stops for that mind and it is dead. The mind, as a living, growing entity has died. And yet the person, in a sense, continues on. Sometimes, I guess, an over-valent idea enters the mind as a problem, or imaginary problem. This is not so rare. You are getting ready for bed, late at night, and all of a sudden the idea comes into your mind that you did not shut off your car lights. You look out the window at your car-which is parked in your driveway in plain sight-and you can see that it shows no lights. But then you think: Maybe I left the lights on and they stayed on so long that they ran the battery down. So to be sure, I must go out and check. You put on your robe and go out, unlock the car door, get in and pull on the headlight switch. The lights come on. You turn them off, get out, lock up the car and return to the house. What has happened is that you have gone crazy; you have become psychotic. Because you have discounted the testimony of your senses; you could see out the window that the car lights were not on, yet you went out to check anyhow. This is the cardinal factor: you saw but you did not believe. Or, conversely, you did not see something but you believed it anyhow. Theoretically, you could travel between your bedroom and the car forever, trapped in an eternal closed loop of unlocking the car, trying the light switch, returning to the house-in this regard you herewith are a machine. You are no longer human. Also, the over-valent idea can arise-not as a problem or imaginary problem-but as a solution. If it arises as a problem, your mind will fight it off, because no one really wants or enjoys problems; but if it arises as a solution, a spurious solution, of course, then you will not fight it off because it has a high utility value; it is something you need and you have conjured it up to fill this need. There exists very little likelihood that you will travel in a loop between your parked car and your bedroom for the rest of your life, but there is a very great possibility that if you are tormented by guilt and pain and self-doubt-and vast floods of self-accusations that hit every day without fail-that a fixed idea as solution will, once it is happened upon, remain. This is what I next saw with Kirsten and with Tim, upon their return to the United States from England, their second return, after Kirsten got out of the hospital. During the period that they lived in London that second time, an idea, an over-valent idea, one day came into their minds, and that was that.--PKD *Transmigration of Timothy Archer*