The missile knows where it is at all times. It knows this because it knows where it isn’t. By subtracting where it is from where it isn’t, or where it isn’t from where it is (whichever is greater), it obtains a difference, or deviation. The guidance subsystem uses deviations to generate corrective commands to drive the missile from a position where it is to a position where it isn’t, and arriving at a position where it wasn’t, it now is. Consequently, the position where it is, is now the position that it wasn’t, and it follows that the position that it was, is now the position that it isn’t.
In the event that the position that it is in is not the position that it wasn’t, the system has acquired a variation, the variation being the difference between where the missile is, and where it wasn’t. If variation is considered to be a significant factor, it too may be corrected by the GEA. However, the missile must also know where it was.
The missile guidance computer scenario works as follows. Because a variation has modified some of the information the missile has obtained, it is not sure just where it is. However, it is sure where it isn’t, within reason, and it knows where it was. It now subtracts where it should be from where it wasn’t, or vice-versa, and by differentiating this from the algebraic sum of where it shouldn’t be, and where it was, it is able to obtain the deviation and its variation, which is called error.
Fascist Nations Shortly after the war of 1914-1918 the first fascist nations emerged in Europe In those nations the sun rose and set at the usual time shedding light on homestead roofs and hills' green slopes Cattle mooed gently in cowsheds Mothers kissed their children's foreheads to wake them at dawn Fathers returning from work with cheerful weariness in their bones smelled the smoke from their hearths and after dinner fell asleep in armchairs or tinkered intrepidly or practiced their music with a passion Children played at stickball at hopscotch and hide-and-seek Little girls sprouted breasts and overnight little girls turned into big girls filled with whisper and murmur like trees in the woods and sudden giggles the sound of which made boys' throats go dry On summer evenings curtains lit from within showed shadows meeting parting and meeting again tenderly Whereas in winter lovers inhaled the steam of each other's breath in snowy gardens And one might also mention cats arching their backs sparrows soaring up above the pavement old women on their porches flowers cut and potted nurses taking patients' temperatures people sweeping streets with brooms One might mention drying wood wind in a thicket damp furrows in a field And one might also call to mind many particulars bearing Witness that For there were no signs on the sky mournful comets burning bushes water turned to blood For life went on as always Hence there truly were in those nations many ordinary people and good people and people who knew nothing and to whom it never occurred and who didn't consider themselves accessories and who had nothing to do with it and who didn't even read the papers or read them carelessly caught up in thoughts of what they had to get done fix the leaking roof get the shoes repaired propose have a beer mix the paint light a candle and who really didn't see the fear in a neighbor's eyes didn't hear the trembling in travelers' voices asking the way didn't see the difference didn't hear an inner voice or if they had their doubts there was nothing they could do and they took comfort saying At least we aren't doing anything wrong we live the way we always did Which was true And yet these were fascist nations
– Wiktor Woroszylski, “Fascist nations”, 1969, translated by Stanisław Barańczak and Clare Cavanagh