Descartes' world-made-anew doctrine
It is always exciting to come across a writer who 'gets it'.
In this instance the writer is Jan Hendrik van den Berg and 'it' is the fateful, overwhelming, gigantic influence of the ideas of Descartes on our modern Weltanshauung.
I've been reading van den Berg's The Changing Nature of Man (1961). Part of his thesis is that when his Weltanschauung changes, not only does man himself change but the world too. So when Descartes supplied us with a new outlook, the world itself began to be made anew -- and not necessarily in a good way.
Van den Berg's starting point, in this book, is the history of the relationship between children and adults, which seems to have changed rather profoundly, over the centuries. There is, in particular, the curious fact that 'adolescence' was never considered 'a thing' before about 1750. Since that date an ever-widening gap seems to have opened up between the realms of childhood and adulthood, needing to be bridged by the crisis called adolescence. The author questions why this might be so. After considering briefly the hypothesis that children have been changing their nature, over the period in question, he concludes that, far more likely, it is the adults who have been changing.
What has happened to us adults is that what we may call the 'quantitative attitude' has crept into our world. But it doesn't stop there. The world has become homogeneous, its mode of causality, uniform and continuous. In this new world, it is more difficult for form, novelty and events to exist than it was in the old, Aristotelian world. They have become problematic, whereas before they were just given. We are increasingly ruled by the past (as illustrated by evolutionary and developmental explanations of our behaviour).
Of course Descartes was not solely responsible for the new outlook. An obvious co-conspirator was Galileo. After all, Galileo even wrote a (notorious) book called A dialogue about the two main world systems (1632). Ostensibly about the Copernican versus Ptolemaic astronomical theories, the dialogue morphs ineluctably into a more general discussion about a new, quantitative outlook versus the Aristotelian, qualitative world-view.
It is rather astonishing that at precisely the same moment that Galileo was penning his dialogue, Descartes was writing his own manifesto Le Monde. In it, he invites us to imagine a new world, its matter consisting of something called 'extended substance' (he would later use the term res extensa). To start with, the new world exists in a sphere of the imagination, but by the end of the book the reader has been well-prepped for the revelation that this imaginary world is actually the real world in which we wake up, get out of bed and have our breakfast.
The date of publication of Le Monde is 1664 making it appear, at first sight, as though it has nothing to do with Galileo's Dialogo of 1632. The actual reason for the late date, of course, is that Descartes took fright from Galileo's fate at the hands of the Inquisition, and decided not to publish Le Monde, which was all ready to go in 1633. By 1664 he was beyond the reach of the Inquisition -- having been dead for 14 years.
Here is an extract from The Changing Nature of Man, to give a taste of the book (pages 52-58 of the 2nd edition). There is no more than a hint here of the author's masterly tying of the Cartesian world-made-anew doctrine to the division between children and adults -- which makes the doctrine into a matter of intimate concern to all of us (not just the intellectuals). For that, you will have to look at the rest of the book.
Continuity
It is the idea of continuity. Nature does not leap, natura non facit saltus. "Tout va par degrés dans la nature et rien par saut." Leibniz with these words formulated the law which he, himself, thought so important, the law of continuity: "La loi de la continuité". It can easily be proved that this idea of continuity has not always been thought true. I shall go into this presently, but before doing so I have to point out that I do not merely wish to show that the idea of continuity has not always been there; it is not the idea that matters so much, as the continuity itself. Previously there had been no continuity of things, and now there is.
We adults effected this change. So intently have we turned this idea into reality, that now, if we should doubt it, we should be doubting reality. Consequently, we are able to say, "You see, reality is continuous." It would stop being continuous as soon as we retracted this idea, which affords children so many hardships. For the thoughts we think become real, if they are great thoughts. That is what thinking means, to make real. If thoughts do not become real, then they are not thoughts, certainly not great thoughts, but playful fantasies which, miraculously, sometimes also touch reality and hang on to it. "Have you noticed," wrote Oscar Wilde, "that Nature has recently begun to look like Corot's landscapes?" Really, is not this a beautiful example! For Corot did not think, he only looked; he played with visions and put them down on his canvas. They flew off it and nestled in Nature.
The foundations of a miraculous science
When was the idea of continuity born? At the beginning of the seventeenth century? Perhaps the birthday of this thought can be identified now with great accuracy. In the beginning of the seventeenth century lived one of the greatest thinkers, a man who changed reality considerably by his thinking; he was involved in an adventure which enacted itself within the borders of a strictly personal existence, within the walls of a small study. The effects of this adventure have determined the existence of many (till now, of all) generations after him.
In November, 1619, Descartes, in the service of the Duke of Bavaria and out of work because there was nothing to do as far as military matters were concerned, rented a heated room in the neighbourhood of Ulm, where he "occupied himself with his own thoughts, in the happy circumstance of not being troubled by worries or passions." On November 10, strange things occurred; thoughts arranged themselves, unknown prospects appeared before his eyes, prospects of a new scientific activity, still vague and not yet fully elaborated, but with fixed directives. Mirabilis scientiae fundamenta, the foundations of a miraculous science were born. What foundations? And of which science? Descartes never answered these questions, as far as we know. But there have been many conjectures. Probably Descartes' discovery (all of his work points to this) is concerned with the possibility of patterning every science after mathematics. What was the point of this discovery? Bréhier, who formulates this question, answers by alluding to a passage in another of Descartes' essays, the Géométrie; in the last paragraph of the last chapter is to be found an observation of universal importance. "If the first two or three terms of any progression are known," writes Descartes, "it is not difficult to find the other terms."
This is the idea of continuity. it had never before been formulated as a universal law, a law to which all things and all incidents had to conform. The concepts of continuity and its opposite, discontinuity, were known in the middle ages as well as in antiquity; but the latter had never been rejected in favour of the exclusive validity of the former. Discontinuity, which means a nongradual transition, a leap, an unconnectedness, and which implies accidental or free occurrence, was accepted in every respect as possible and real. Now discontinuity seems almost inconceivable. We have become so used to connection and gradual transition that we cannot think of anything unconnected. We look for structures; driven by a quaint necessity, we desire connections, gradual transitions. That a thing could have structure without connection (without the connection of gradual transition) is unimaginable to us. And yet it is only possible to speak of the structure of things and incidents if there is no continuous connection. For continuity equalizes; it ultimately abolishes all structure. It produces homogeneity; and there is nothing so devoid of structure as homogeneous matter.
Descartes' principles
But I do not express myself correctly. It is not continuity that produces homogeneity, it is the other way round; homogeneity is a condition for continuity. The idea of gradual transition would not have occurred if the things, between which the transition was supposed to be made, had not previously been made equal.
I will try to prove this by citing Descartes' Principes de la philosophie (1644)· The second part of these principles of philosophy is concerned with "Les principes des choses materielles," which is an elaboration of what Descartes wanted to express in his idea of continuity. His argument is based on a few cardinal observations. They are:
1. Neither its weight, nor its resistance to touch, nor its colour is typical of an object; only its extensiveness is essential. [If a paperweight loses its weight it still remains an object; if it flows away between my touching fingers, and if it changes color, it is still an object. In spite of all these not unimportant changes, the objectiveness of the object remains untouched.]
2. What has extensiveness, is an object. [This conclusion follows immediately from the first thesis; if smell, taste, shape, weight, consistency, in short, if anything that is variable is not typical of an object, then it can only be circumscribed by that which is in- variable: extensiveness. The object occupies space.]
3. What has extensiveness can be divided; the parts necessarily still have extensiveness, and consequently can be divided again. This division goes on infinitely; there are no atoms. [This thesis also follows from the previous one; if matter is only extensiveness, then it can be divided infinitely, for every measure can be halved.)
4. Everything consists of the same matter. [That is clear; if matter is only extensiveness, then every matter is alike. As, obviously, there are differences between objects, the next thesis follows.]
5. The difference between objects is a nonmaterial difference, a difference in motion. [I shall return to this thesis presently. The question which this thesis invites is: Where does this motion come from?]
6. Motion is caused by another motion. [After this, the next thesis is inevitable.]
7. The first motion was initiated by God.
The final principle is the first thought
It is done, it cannot be denied: God has been eliminated. For, as a rule, in such closed lines of thought, the last thought is the thinker's starting point, the thought that matters. Descartes wanted to eliminate God; God who previously had literally been present in all things. This is all over now.
Let us see how Descartes takes God by the hand. He starts by saying: Only its extensiveness characterizes an object. The object occupies space; everything else is unimportant and can just as easily be dispensed with. Is it not true? A paperweight is just as much a paperweight, if it should flee from my fingers, if it has no dureté, no resistance to touch, or if it has no weight or colour. This idea seems plausible.
Yet it is not true. No one would need a paperweight without weight; its weight is what matters. The paperweight which flees before my pointing finger would be highly inconvenient, if not dangerous. If all things lost their dureté, their resistance to touch, no one could either use or enjoy them. It would not be possible to stick a potato on a fork; one would not even be able to pick up his fork. And finally, the paperweight whose colour changes might well clash so much with the colours of other objects among which it has to occupy space that it would be wise to flee; for using its resistance to touch and its weight, its owner would certainly throw it in the wastepaper basket.
A matter of being scientific
The reader who might think that I do not mean this seriously is mistaken. I am serious. The way Descartes treats objects is not fair. If science wants to consider objects as they are, in the form they have as objects, then it is not permitted to speak of objects which consist of nothing but extensiveness. There is no such thing--and there was no such thing. But Descartes' ideas have penetrated so deeply into reality that nobody knows where the idea ends and reality (or, if preferred, another idea of reality) begins. We shall see this presently.
Descartes' arguments
Descartes' first assertion was: extensiveness is the only essential characteristic of an object. This assertion contains a reduction which is not scientifically justified. The second assertion restates the first: what has extensiveness is an object. The reduction is the matter itself. So as far as objects are concerned, nothing matters except length, width, and height. This assertion gives us a right to speak of nothing but extensiveness if we are discussing objects, which is exactly what Descartes does. Objects are infinitely dividable (which follows immediately from the thesis that extensiveness is infinitely dividable), and everything consists of the same matter (everything has extensiveness). The inevitable result of this is: objects are identical (a piece of bread is a brick), and the difference between objects (a piece of bread happens not to be a brick) is a trick of extensiveness. And the only trick extensiveness can play is one, which, like extensiveness itself, can be expressed in numbers, in length, in width, and in height: that is, motion. If things are only space, locations in space and no more, there is nothing to consider but going from one location to another. Motion, however, so argues Descartes, requires a reason, or (which is not the same thing) a cause. One motion causes another, resulting in an endless series of motions. Where is the beginning? But who can imagine infinity? any attempt would make us dizzy. Rather have a beginning somewhere, a first motion started by a first mover: God. God once gave our world a push and it has kept on moving since, one motion causing the next and so on; the total quantity of motion remains the same, nothing is added--for that would only confuse the issue. We also know, says Descartes to his own and our assurance, that God is perfect; not only is His nature unchangeable, neither will He undo what He initiated. Here Descartes surpasses Pangloss.
Pascal saw through Descartes' intention: "He [Descartes] would have liked to do without God, but he could not avoid letting Him give a little push to set the world in motion; after that he is finished with God." That was what it is all about. Descartes protested against an Aristotelian idea of causality, which is open to all sides, which leaves room for unknown causes, for qualitates occultae that can act anywhere at any time; an idea of causality that causes a breeze of insecurity to blow through incidents. Descartes wanted to invalidate this conception; how many times in La Flèche had not people boxed his ears with it? Now that's finished (one can almost hear him say it); he locked away reality from anything that does not conform to strict continuity. There is no room for God anymore, except in the beginning. But that is only a safety measure; if God were nowhere at all, if He were not ordered to stay somewhere, no one would know where He might suddenly reappear. That is the reason for Descartes' complicated argument, for his reduction to extensiveness. For only in this system are all things identical, and only through this homogeneity is there a strict causality. The way from now on is in one direction only, not to be averted, and predictable. It is dependable, this way; so much so, that it can be examined and laws derived to which incidents of tomorrow will conform. The experiment becomes possible. What is valid now will be valid forever.
The past character of the experiment
It must be stressed that the idea of continuity is a result of a homogeneity which was produced by reduction. If this reduction -- objects are localized space, extensiveness -- is valid, then, but only then, is the idea of continuity valid. If the reduction is accepted, the experiment has sense; but only if. The experiment is valid for a denuded world, a world of naked localisation, not for any other world. The experiment, according to Fechner, belongs to a "night view," not to a "daylight view."
How can experiments discover laws which will be valid tomorrow and in a thousand years? (These laws make it very easy for us to believe in the "objective accuracy" of genetic continuity.) The answer is obvious. The experiment is part of a world which is reduced to extensiveness: the experiment measures. This reduced world is a homogeneous world; it only contains identical things (for every measure is measure), and therefore it is continuous. The present is like the past: measure then is measure now; the numbers may vary, but numbers are infinitely dividable. The present is an elaborated past, a consequence of the past. And so the present is made the past, insofar as it is what necessarily results from the past. In this sense the future is the past, too, it is also what necessarily results from the past. There is no doubt about it: the experiment, directed at a reality which had been carried back to the past, discovers laws which are valid in the future, for that future actually is the past From which these laws were collected. The entire predictability of science is based on the "past" character of its "nature." Science predicts nothing, it only seems to do so by laying expectations in the future-a future, however, which long before was made past. The expectations come true because the predicted incident is chained to the past. Only by relating incidents to the past do they become predictable.
To predict, to really foretell, is still a gift of those who own the future in the full unrestricted sense of the word, the sense of what is coming toward us, and not of what is the result of the past.
These remarks can be illustrated and made clear with a concrete example.
[The author goes on to describe Foucault's famous experiment with a pendulum in the Panthéon.]
Note:-- I found the statement (in the above) that resistance to touch is not typical of a material object somewhat disconcerting. How can we make sense of a world constructed out pieces of matter that can move, but are also capable of inter-penetrating one another? I would claim that it is impossible -- and certainly cannot lead to a machine-like world as envisaged in Le Monde and more generally in the 'mechanical philosophy'. Indeed Descartes did grant the property of impenetrability to his matter; but it is true that he regarded this property as more accidental, less essential, than the absolutely essential attribute of extensiveness. Gaukroger has a useful passage on this in his Descartes: an Intellectual Biography (1997), page 367. He considers that impenetrability was less acceptable to Descartes, at a fundamental level, than extensiveness, because he couldn't see how the property of impenetrability could be expressed in purely mathematical terms. This would be less of a problem to a philosopher working today, since the of development of the mathematical Mechanics of Continuous Media -- in plain words, the mathematics of stresses and strains. In any case, Gaukroger says, 'impenetrability, Descartes believes, is a direct consequence of extension'.