Hans Jonas, Philosophical Essays, “Seventeenth Century and After: The Meaning of the Scientific and Technological Revolution”
VII
After this analytical summary of the direct conceptual content of the theoretical revolution in dynamics, a brief metaphysical evaluation of it is in order. We said at one point that what the innovation was originally about was not the time-honored principle of causality per se, but the conception of change. We must now add that the altered conception of what constitutes a change, i.e., an effect, naturally reacted on the conception of what constitutes a cause. Now, “change” had been redefined as acceleration of mass, and to this its primary form all (phenomenally) other kinds of change – such as qualitative change – must be reduced. Accordingly, “cause” is redefined as that which imparts (or resists) acceleration – i.e., as force, whose sole effect is acceleration (or its negative), and whose magnitude is precisely measured by the amount of acceleration it imparts to a given mass: and to this, its primary form, all (phenomenally) other kinds of “causes” must be reduced. From this simple correlation, extraordinary physical as well as metaphysical consequences follow.
First of all, with the quantifiability of all changes in nature, the cause-effect relation has become a quantitative relation, namely that of strict quantitative equivalence of cause and effect. To be the sufficient cause for an event means to be sufficient in quantity for the quantity of change which that event represents, i.e., of equal quantity. The presence of such a quantity is therefore the sole – necessary as well as sufficient – cause for the effect: its antecedence is to be postulated when the effect is the given; contrariwise, the succeeding of the latter is to be deduced (predicted) when the cause is the given. Consequently, any physical state can be represented as a determinate configuration of masses and forces from which the next state follows necessarily and – more important – can be computed rigorously by a calculus of the represented magnitudes, if all of them are known.
However, to the last qualification there must be added this one: unless in the interval new magnitudes of this sort – forces or masses – appear spontaneously ex nihilo or given ones vanish into nothing. That this does riot, nay cannot, happen follows in no way logically from the new system of concepts themselves; but it is their necessary metaphysical corollary, for without it, i.e., with the possibility of physical magnitudes appearing and disappearing, the assertion of quantitative equivalence and of computability remains vacuous. The constancy of matter and energy (or matter-plus-energy) is therefore an indispensable axiom of modern science. In its implied negative aspect it means the denial of the possibility of any nonphysical, e.g., spiritual, cause intervening in the physical course of things – in short, the denial of the possibility of miracles, which in the last analysis involve either creation or annihilation. That they themselves would be proceeding from a cause, e.g., the will of God (thus complying with the general principle of sufficient reason), does not make them any the more reconcilable with the new idea of causality in nature, which demands that every physical event be accounted for by purely physical, i.e. material, antecedents in the quantitative sense we have described. This exclusion of miracles, generally and tacitly held at least as a methodological assumption, Spinoza alone of the philosophers of the new creed – its enfant terrible – had the boldness or indiscretion to spell out as a metaphysical certainty.1
But just such a “miracle,” by the terms now defined, would be the most ordinary initiation of an external change by an act of human, no less than by one of divine, will, because this would start a new causal train “from nothing” as far as physical antecedents are concerned: and the new metaphysics of science showed its determination by braving the clash with this our most immediate and common experience (viz., that we are authors of our actions from purpose and design) and by going to extravagant lengths of metaphysical construction so as to be able to relegate this basic experience to the realm of mere appearance. Here the fideistic quality of the new stance comes into the open, as both assertions – that of “subjective” experience, and that of “objective” science which denies it – are equally beyond proof or disproof.
Thus not only intervention by a transcendent, extramundane cause but also any intramundane mental causality is ruled out. Things do not stop there. Ruled out from the mundane universe are, together with the causal efficacy of human purpose, end-causes of any kind – i.e., teleology as such which, in whatever attenuated analogy of striving and satisfaction it is conceived, must share with human purpose a transmaterial, quasi-mental aspect. That Nature is devoid of even the most unconscious bias toward goals/ and of the formative power to serve it – that final and formal causes are struck from its inventory and only efficient causes left, follows simply from the principle of quantitative equivalence and invariance in cause-effect relations which is the distinguishing mark of the “determinism” of modern science. This determinism must not be confounded with any premodern beliefs in fate, predestination, predetermination, and the like. It actually is opposed to them because it excludes the future-reference indicated in the prefix pre-. It means that always and only the immediate antecedent determines the next instant, that there are no long-term trends toward something, but only a transfer of the mass-energy sum from moment to moment, and the vis a tergo of this propagation – in short, no pull of the future, only the push of the past.
And a metaphysical proposition it is: Kant’s later, ingenious (one is tempted to say cunning) attempt to transform it into an epistemological proposition, whereby the impossibility of miracles means that they cannot be “experienced,” thus evading the metaphysical issue, remains as far below Spinoza in metaphysical straightforwardness as it is above him in subtlety. The attempt, incidentally, is a failure. For it is simply not true that a sudden emergence “from nothing” of a substance or force, or any exceptional violation of the constancy laws, would explode the ordered totality of our “experience” and reduce its unity to a shambles. True, it would be a startling and disconcerting experience, but then, miracles are supposed to be startling and disconcerting. The simple truth is that the concept of rules (other than logical) is perfectly compatible with the concept of exceptions there from; and should they happen, they would be experienceable precisely as such, i.e., against the background of prevailing rule. Admittedly there can be no science of the exceptions (since science is concerned with the rules), but whoever claimed that there is a science of miracles? Only when “experience” is defined as (and thereby restricted to) the context of that which conforms to universal rules throughout and thus is indefinitely open to scientific correlations, is it true – but also trivial – to say that miracles do not fall within “experience”: it is a tautological statement. Such a tautology does not take one off the metaphysical hook. In honest fact, the conviction that miracles never happen is as much a “faith” as is the belief that they may happen. The former is superior only as an injunction to always seek for a natural explanation – which the latter may tempt one to neglect (Spinoza’s argument of the asylum ignorantiae). However, the injunction itself means that what stems to be a miracle must not be accepted as such: but that “seeming” itself is an experience, and the confidence that it will eventually be disproved is only a posteriori vindicated. The exclusion of miracles is thus a veritable article of faith in the metaphysics of science: so much so that (as shown in the next paragraph) it is pitted against a class of “miracles” nobody can deny to constantly experience himself – without this fact, of course, proving their truth, for there can be deceptive experience. ↩