What exactly is Cartesianism, that 17^th Cosmology which refuses to die?

It is the general term for a cosmology by which Descartes proposed to reduce all material to infinitely divisible (and by implication infinite) mathematical extension — length, breadth, thickness — a universal homogeneity.

In a word, two factors alone are needed to explain the world: homogeneous mass and communicated local motion, capable of being transmitted and transformed in numberless different modes.

This, whether in a materialist understanding of mechanism, or accommodating a metaphysical prime causality extrinsic to the "machina", more or less describes the position as regards the "natural philosophy" of many modern scientists, either unemphatically or emphatically.

But there have been Atomist movements that tended to ebb and flow around a form of neo-Mechanism as well, sometimes termed Energism. The neo-Mechanists are less dogmatic; instead of laying down categorically that all properties of matter are only local motion, they are content with saying that the reduction of all properties to motion ought to be the aim of all scientific explanation, and that this end will perhaps be attained by the science of the future.

They admit however that such an explanation is faced with grave difficulties, if indeed it does not lead to real contradictions.

Neo-Mechanists and Positivists also refuse to pass judgement as to the real nature of things, on the grounds that it is not the province of science to solve metaphysical problems.

But as a matter of fact these differences are largely incidental, for in both systems, the only accidental reality which is taken into account is local motion; it is the sole agent admitted, whether definitely or tentatively, to explain the entire order of material phenomena.

With regard to the substance of bodies, although neo-Mechanists are unwilling either to define or even to admit it, it remains true that logically this substance must be homogeneous; since if all properties are reducible to motion (as such actually homogeneous by necessity), it is arbitrary to introduce qualitative distinctions between substances which support these different properties.

The theory of energetics (energism) is a reaction from Mechanism, a new form of dynamism.

A major reference and authority in this study will be the positivist physicist and historian of science, Professor Pierre Duhem, Member of the Institute of France who was sympathetic to a form of impetus dynamism while insisting that the physical sciences were autonomous and developed, as he put it, by gradual evolutionary progress; a process that also involved competition, intuition, and correction — irrespective of whatever natural philosophy attached to it or was attached to it.

It must also be noted at once that Descartes also somehow contrived to "patch on" to his mathematical cosmos and particularly his doctrine of local motion, the concept of impetus (provided initially by God) by which device early mediaeval physicists had managed to break free of the ancient Aristotelian fatalism — an expression of pagan theology.

The classical understanding of Cause is quite in keeping with modern thinking.

A Cause is simply an explanatory principle. Aristotle proposed four principles of explanation — material, design, the maker (or changer), and purpose (or end).

Whereas only two of these are commonly admitted to be associated with much of the mainstream modern philosophies of science, the exclusion of the others can, at times, seem synthetic or forced.

No doubt this simplification was encouraged in the cause of the rigorous positivism which had arisen earlier this century in astronomy, physics and chemistry, but soon became confused with philosophical methodology; and within a few decades, through Comte, overwhelmed ethics in the guise of a positivist social physics (sociology). (Henri de Lubac The Drama of Atheist Humanism Appendix A)

However it remains difficult to explain how the full frame of causation can be excised from the human processes of ratiocination, i.e. the four questions mirror a perfectly natural psychological dynamic.

In short, it is sometimes evident that, even if one of the four explanatory principles has been rejected, the fact that it had to be invoked in the first place (or might have been) is proved by that very rejection. i.e. Dawkins' denial of design (formal cause) and his taking refuge in the bastard word "designoid" which he posits as a neutral term in an attempt to avoid the implication of "designer" (primary efficient cause) exemplifies at least one way to avoid problems that arise in a cosmology where, as an a priori, a teleological dimension is denied.

Some scholars claim that this post 16th tendency to be selective about the Peripatetics' "four causes" is first discerned in Descartes himself; as one of the earliest, if not the first exponent of causal selectivity. The logical consequence of his own Mechanics is to exclude the real nature of specific entities because of the homogenising essence he proposed in his cosmology of infinitely divisible geometrical extension which he says, as I have indicated, is "moved" only by local or contingent influences. This at once avoids the question of form other than as a wide generality or universal; (how does one explain away the form of Cartesian vortices?) but form remains, for all that, one of the key causes men naturally seek; "What’s this supposed to be then?".

This approach was further affected by Descartes’ conception of metaphysics itself (Descartes Principia Philosophia) which he made absolute mistress of the physical sciences (in opposition to the usual classical custom followed until then which left each science of secondary causation to be mistress of her own kitchen …

"The Philosopher must wait upon the physicist" — Aquinas."

Insisting that the scientist should begin his enquiry from metaphysics, [Descartes Letters] Descartes invited two immediate discrepancies; first he proposed one rule whose very tenet he would deny with another — both in the name of common sense. For the first (philosophy) is the scientific development and perfecting of common sense (or was accepted as such in his day) and the second (physical science) is the immediate product of common sense.

"It is undeniable that to be proficient in the sciences it is not necessary to be a philosopher or even to base one's work on philosophy. Whereas philosophy alone enables a man of science to understand the position and bearings of his special science in the sum total of human knowledge." (Jacques Maritain. Introduction to Philosophy. 1944).

It is also difficult to deny that it is from common sense, or from the natural evidence of the intellect and experience, that the sciences derive their postulates — from which arise experiment, induction, and exclusive testing to distinguish a really contingent secondary causation.

Thus in the most immediate respect, the teleology of his formal object is fudged, and another "cause" is discredited, viz, end. By this he doubly eliminates purpose, for, as I pointed out above, mathematical essentiality finds no place for it; and that is the crux of his cosmology.

To examine the consequence of this disturbance of explanatory principles is, perhaps, no more than a secondary burden of this essay; but at the very start, while one must welcome Descartes' insistence that there are as many things as there are clear and distinct ideas (incidentally, a proposition that opens the door to some confusion between physical and metaphysical principles in his own system where material entities are merely conformations of one universal substance), the fact remains that if two distinct intellectual disciplines, such as the methods of examining natural phenomena and the methods of seeking ultimate causes, are confused, or even intentionally pressed into one conglomerate science, certain anomalies can only be expected.

At this point I must declare my own present position as to the limits of physical "explanations" in the domain of physical theory — which, since Comtean positivism has reduced all philosophy to science (and in doing so abandoned the concept of philosophy altogether) takes the place of natural or science philosophy:

A physical theory cannot be taken as an explanation until every sensible appearance has been removed to allow us to grasp the physical reality. Newton’s research distinguished the sense experience of light from the physical phenomena underlying that experience. For example, that light was a complex of simpler phenomena each of which had a determinate colour which never varied. But the simpler data are abstract, only generally representing the viewer’s own sensate experience. Quite simply they are "sensible" experiences. What Newton did was to dissociate a complex experience into simpler ones. He had constructed an optical theory but had not explained the colour effects.

The attitude is certainly gaining ground among scientists with whom I work that Physics is a translation of data through mathematical symbolism. The logical analysis of sense data. One might even describe it as a convenient aid for memory. Hypotheses in physics have in themselves no relationship whatsoever to experience, that is, to the real world, and that physical theories as such have an altogether relative character. I would add that while admitting the absolute need for inductive examination in empirical and experimental design, deduction is ultimately inevitable (or there can be no philosophy of science) but that, for many of us today, that deductive reasoning could be described as analysis and synthesis. But this does not preclude a metaphysics which protects physical theory without violating its autonomy because it can be argued with Pierre Duhem: "The belief in an order transcending physics is the sole justification for physical theory."

I present these reflections, not to attack Descartes' position as such; but, in order to preserve a sense of proportion, to set out as early as possible, even from the mind-set of my own generation, the sort of problems that attend any in-depth examination of Cartesian principles, especially if these affect his causalities.

Again both the mind-set of his time, compounded of those particular ideas which Descartes thought he had overthrown but which in fact remained and betrayed their ubiquitous presence in much of his writing; further muddy the Cartesian water for an exacting scholar.

It is unarguable that Descartes’ philosophy consumed his science inasmuch as he made metaphysics the key to explaining things, as Comte in due course would excise philosophy by having science consume it.

For his part, he can scarcely be called the intentional enemy of the schola’s rigorous classicism; although he certainly knew he was kicking over Aristotle’s physics, as he confided in a letter to Mersenne. But surely he must have known that, where it mattered, i.e. in the domain of statics and dynamics, this had already been thoroughly effected — indeed such problems from the time of Tempier had never really been ignored despite the latent Renaissance humanist propaganda which continued into his time. (See Chapter Three)

His breakthrough was ultimately for physics though, and, despite his protestations, left his metaphysics effectively sidelined in the end, even unfulfilled I propose to prove. (See Chapter Four).

Here is Professor Etienne Gilson, remarking on the already widening fault line between metaphysics and natural physics: "Scholastic Philosophy actually died to the extent to which its philosophy of nature had been mistaken for a science of nature … mistaken both by itself and by its adversaries.

This is as elegant a setting out of the stage in which Descartes made such a grand entrance as I have been able to find. But, fascinatingly, it could also help explain just why the Descartes show is still running.

However, Gilson argues that, having taken that step, the new philosophes did not seem very much to bother about metaphysics itself, except in order to show that this new conception of the world of sense did not make it impossible for them still to prove the existence of God….

"What the great 17^th century philosophers actually did was (rather than to destroy mediaeval metaphysics) to save all that could be saved of it, and in so doing they took a great many things philosophically for granted." (ibid)

Descartes, for instance, objected about the classical tendency of the time to obscure self-evident things by over-defining and explaining, the futile attempting to "prove" what today we might term irreducibles, a folly that easily slipped into fatuous circular definition, "we're here because we're here" sort of thing..

Molliere's who was a regular visitor at Gassendi's house is attributed with this joke against Schoolmen:

A doctus bachelieurus was asked:

Demandabo causam et rationem quare Opium facit dormire?

(What is the cause and reason that opium causes one to sleep?)

And he answered:

Quiat est in eo

Virtus dormitiva

Cujus est natura

Sensus assoupire.

(Because there is in it a dormitive virtue whose nature is to cause the senses to become drowsy.)

Pascal wrote contemptuously of that favourite Cartesian joke: "There are some who go to the absurd extreme of explaining a word by the same word. One of them I know defined light as follows: "Light is a luminary motion of a luminous body" as if we could understand the words luminary and luminous without understanding "light."

He was alluding, of course, to Pere Noel, who had taught Descartes at La Flèche and went on to become his pupil’s disciple.

He had ill-advisedly written to Pascal: "Light or rather illumination, is a luminary motion of the rays constituting lucid bodies which fill transparent bodies and are not moved luminarily except by other lucid bodies."

Pascal snorted: "To attribute light to a virtue of brightening, to luminous corpuscles, or to a luminary motion, he is an Aristotelian, an Atomist or a Cartesian respectively; but if one boasts of having in that way added a particle to our knowledge concerning light he does not have a sound mind".

I shall return, as I examine his metaphysics more closely, to his Jesuit education and attempt to trace the influence of Suarez who embodied scholastic philosophy so far as Descartes was concerned. (See Chapter Four)

Which brings me to another problem facing the student; to keep a balance between Descartes’ past and his own time in the history of intellectual development; to avail oneself, from the advantage of hindsight, of the historical drama of Cartesianism struggling to succeed other systems, triumphing, maturing and finally failing (where it failed) without falling into the temptation of assessing Descartes himself too severely in that light. Nor must the perfectly valid examination of weaknesses lack charity and proportion to turn into negative nitpicking. In an essay whose subject is to focus on what has in one of its elements experienced decay this is perhaps the hardest exercise in discrimination of all — for it is all too easy to paint the horse’s hooves larger than the horse. I need not remind whomever examines this effort that whatever its shortcomings, a peevish attitude towards this genius whom I admire is the very furthest thing from my mind.

Meanwhile, on the basis that "explanation", in the simplest understanding of that term, can be applied to the whole as well as to its parts, it should be in order for us to ask for the explanation of Cartesianism as such before progressing to its scientific, hypothetical and philosophical applications.