Destutt de Tracy introduced ‘ideology’ (in the French form) in 1796, but applied it only to the study of ideas in the straightforward sense. In the 1840s Marx and Engels introduced a new level of complexity, using the word to indicate a system of ideas which can affect people without their knowledge. They recognised only the effects upon their opponents but this, too, has begun to change, some academics now using the term objectively and some politicians coming to accept that ideology affects their own movements; even the suggestion that ideology constitutes social reality can perhaps be said to have won a place in the debate. One limitation remains unchallenged: ideology affects physical reality (by way of its effect upon human action) but does not rank on the same level and most certainly does not itself constitute that reality. Here we take this as our starting-point.
The physical world exists independently of our awareness; material objects stand solidly there and we live within the limits they impose. This view has become so orthodox, among people who reflect upon such things, as to seem self-evidently true; it comes as a shock to find respected thinkers suggesting otherwise. Yet Wittgenstein held that no real world appears outside intellectual states,  while Heisenberg’s Uncertainty Principle implies that only the act of observation brings phenomena into being. 
Views like that seem to exhibit intellectual perversity in full flower. Of course there is a real world. Why, you can see it. And if you get hit by a falling brick you will feel it. This robust response misses the point. Wittgenstein did not assert the absence of a real world, only the absence of one outside all intellectual states, and Heisenberg did not question the reality of observed phenomena. We can indeed demonstrate, conclusively and if need be forcibly, the reality of the sensible world, but not its independence of thought. We cannot demonstrate anything without thinking about it, and thereby barring ourselves from showing it to be independent of our thinking.
The material world existed before people or their thinking appeared? We have good reason to think so but we do, precisely, think so. All our knowledge of pre-human times comes from thinking about evidence now available, and the same holds for the persistence of the tree in the quad. We have good reason to accept this also, but again as the outcome of a train of thought, not as something existing independently of our knowledge.
Everything so far said concerns the intelligible world. What of the simply material world that acts upon us whether we think about it or not? There may well be such a world, but we already know this and if we know more, if we know that it does exist, this merely confirms its connection with our thinking.
All arguments in favour of an independent world defeat themselves since argument can present nothing unknown to the speaker. Those who mean by the phrase a world of metaphysical substance, not accessible by way of the senses, and those who thump the table, saying: “There, that is real, that is independent of thinking. You can’t get round that,” have this in common: they speak of a world present to thought, one whose independence remains a bare assertion.
Belief in a world independent of thought but accessible to the senses depends for its validity upon the reliability of these, and although this serves everyday purposes it does not stand up to any careful testing. Put one finger for a few seconds in hot water, another in crushed ice, then both in lukewarm water; one will report it hot, the other, cold; the impression cast by the lens on the retina hangs upside-down, and the intervention of a microscope transforms the impression of a cutting edge into one of a blur.
Since no two people occupy the same place at the same time, no two sets of observations exactly correspond; so far as the senses go each of us receives evidence different from that provided to everybody else, and although the assumption of a single world as the object of all these observations enjoys practically panhuman acceptance, this does not guarantee its validity. Taken directly, the senses report a multiplicity of separate impressions; any conception of a single, solid, enduring, self-consistent world ‘out there’ comes largely from rational criticism, analysis and reordering of their indications. It comes, that is to say, largely as an intellectual construct, and it therefore varies with the mode of intellectuality, the ideology, used in its construction.
With five billion people alive, and millions of them often living closely together, it seems unlikely that their various worlds should differ widely, and in fact for the most part they overlap. (Thereby rendering the assumption of a single world more plausible). Even so, differences do persist, and the student can hardly tackle that number of people as separate individuals; fortunately they form themselves into groups according to the main features of their way of thinking, and the socially-significant distinctions appear mainly between the groups of personal worlds constructed (from sense-impressions) by these groups of people rather than within them. From now on I shall reduce the complications by ignoring personal differences, speaking as if the members of each group all inhabited a single world. (I shall also ignore movements of people from one world to another, concentrating directly upon the worlds). Relations between these group-worlds display almost endless complexity, but they can usefully be seen as concentric, with numbers of inhabitants diminishing towards the centre.
Outside the others, embracing them all, lies the world of everyday life, and here the day does not have an unchanging twenty-four hours; its length varies with the seasons. Electric currents need no special instruments to reveal their presence; we flick a switch, and if the light doesn’t work then the bulb or the fuse has blown. Chemical analysis lays no part, food and drink being pure provided they smell all right and don’t make us ill. No quantities occur too small to measure with teacups, spoons, a wooden ruler or the kitchen scales, no gradations finer than the familiar parts of an inch. A recipe will call for a ‘pinch’ of salt and the number-series runs: one, one-or-two, half-a-dozen, a dozen, a lot. The sun moves across the sky, the stars are lights up there, the earth as flat and immovable and matter as solid as they appear. This world has its regularities, but we know of them only from accumulated experience, not from critical examination, and reliance upon them has to be qualified. Luck plays a part; the dropped glass may or may not survive its fall, the arrow misses or strikes the target as an unpredictable fluke of wind takes it, good wishes are worth voicing, and “Drop dead!” not to be lightly spoken. Here physical objects do not all attract each other according to their mass and the distance between them; the floor does not come up as the teapot falls down. Action and reaction are not equal and opposite; when we throw a ball we do not get pushed backwards. Colour inheres in the object, it has nothing to do with selective reflection. We all inhabit this world for the greater part of our time, and its correspondence with the above description (or something close to it, for here accuracy is not to be found) is demonstrated by the general success of our actions governed by this thinking.
Some, for part of their time, move inward from the all-embracing circle of private life into a social world, one where they enjoy greater powers at the cost of complying with narrower restrictions. Here things are not always what they appear to be; rather what the boss, or the foreman, or the book of rules, or the professional ethics, or the referee, or the priest, or Parliament, or the judge or God or some other authority says they are. The bread within reach is not available to hunger if the law says otherwise, but provided the inhabitants of this world comply with the appropriate set of requirements they exercise, jointly, powers far exceeding the personal abilities of any one of them, sharing in the control of mighty systems and massive machines, abridging distance and creating commodities. Here they deal no more with penny packets; prairies of corn and shiploads of ore take their place. Put a brief note in the fax and a thousand cars come from Japan. In this world materials and quantities grow far beyond what can be picked up and put where wanted, or cut to size with a knife, and they display powers of resistance and self-determination not encountered in the first world where activity remains small-scale and for the most part individual. Greater resistance calls forth greater powers; when social requirements change whole productive systems get diverted to different purposes, turning out swords where formerly ploughshares were made. Here the transient impulses guiding so much of private life find no place; system and regularity rule. The indefiniteness of the first world rendered the effects of actions uncertain and prolonged effort largely pointless; where luck may bring or withhold success sensible people take things easy. The second world has a new firmness, a predictability enabling large numbers to join in common tasks extending over long periods; it contains the canals, the Pyramids and the great cathedrals. Brought into being by social activity guided by social thinking, it has to be maintained in the same way. Identification with the established conventions and traditions, both written and implicit, is required of intending immigrants.
Some inhabitants of this second world undergo the rigorous training required for the discovery and exploration of the third. Here they find objects composed of hard-edged particles sharply distinct from each other, imposing rigid limitations and subject to definition, to weighing, measuring and counting. Unlike the approximations of the statute-book, their application subject to judicial decision, the laws in operation here work automatically and exactly; here the apple does attract the earth, as well as the earth the apple. The inhabitants of this world can reasonably hope to develop a system of thought permitting exact prediction of its behaviour. (Further worlds lie inside the third, but being ones in which life and society take priority over material entities they remain outside our present concerns).
Thought enters into the making of these worlds, and for each of them a distinct mode of thought, a distinct ideology with its own logic. In the first, the difference between x and non-x remains indefinite and changeable; successful action here adapts itself to the circumstances of the moment. The second ideology holds x and non-x distinct in principle, producing a world with a new firmness enabling consistent behaviour and collective action. The third ideology values the rigour that appears in Aristotelian logic, where nothing is both x and non-x, and in this world the scientific pursuit of precision finds its place. The distinctive features of each world arise from the particular qualities of the ideology that went into its making.
1. Alan G.Gross 1990 The Rhetoric of Science Cambridge Mass: Harvard UP 50/51.
2. John D.Barrow ‘A Sea of Particles’ TLS 10 January 1992.
from Ideological Commentary 58, November 1992.