Causality in the Islamic Outlook and in Modern Physics

Mehdi Golshani

 

According to Blackwell’s Dictionary of philosophy determinism means that every event must have a deterministic cause, i.e. a cause which ensures its occurrence (Mautner, 1996). Often determinism is used in the sense of predictability. But, these two are not the same. If causality holds and if one knows all the laws of nature and all initial conditions, then one can determine the future. But, it is possible that causality holds, but we might not be able to predict the future, due to our lack of knowledge about the laws of nature or the initial conditions. Causality is an ontological issue, whereas, predictability is an epistemological one.

Gradually causality was used in more restricted senses by physicists and finally the thesis that (i) there are universal laws and (ii) one can determine the future of any physical system by using these laws, was interpreted as determinism and was identified with causality.

This kind of determinism came under attack during the nineteenth century. Thus, Renouvier, e.g., disputed the strict validity of causality principle as a regulator of physical processes. Charles Peirce, American mathematician and physicist, gave chance a fundamental role in nature. In his view, the world is not strictly governed by Newtonian laws. It is also ruled by laws of chance. Boltzmann, Exner, Poincaré, etc. all disputed strict validity of determinism and speculated that the laws of nature are statistical in character.

Against these, some physicists (e.g. Planck, Nernst, etc.) refuted the statistical character of physical laws and attributed their use by humans to ignorance.

The first serious blow to causality came from Heisenberg’s uncertainty principle. Using a Gaussian wave packet to represent microphysical entities and finding its Fourier transform, Heisenberg obtained the following relationThe statistical interpretation does not negate the existence of hidden variables. In fact, it encourages the search for such variables. Thus, in the statistical interpretation, determinism is not necessarily refuted.
Uncertainty relations may have other interpretations than Heisenberg’s own interpretation (see e.g. Popper’s interpretation or Bohm’s interpretation)
Born explicitly admitted that his refutation of determinism had been a philosophical decision, rather than a physical one.
There is no convincing argument for the denial of a sub-quantum level, in which strict causality holds.
The appeal to indeterminancy for the explanation of human free will is not right. Because, even if we base decision making on physical processes, it is the result of the behavior of a macroscopic ensemble of particles not a single particle. Thus, even according to the standard view causality should hold. On the other hand, even though causality does not prove human freedom, it is not in consistent with and it even supports it. Because, without the applicability of causality how one can attribute any action to an agent.

The uncertainty relations do not prove that atomic object do not process exact coordinate and momentum. To reach Heisenberg conclusion, one has to add the extra assumption that only observable objects have reality. Some of the physicists who denied causality, were merely denying some of its archetypes, not the principle of causality itself. As Born put it (Born 1944, 3-4) :

The statement, frequently made, that modern physics has given up causality is entirely unfounded. Modern physics, it is true, has given up or modified many traditional ideas, but it would cease to be a science if it had given up the search for the causes of phenomena.

Born adds that he has problem with the orthodox interpretation of causality (Born 1944, 101-102) :

Can we be content with accepting chance, not cause, as the supreme law of the physical world ? To this question I answer that not causality, properly understood, is eliminated, but only a traditional interpretation of it, consisting in its identification with determinism. I have taken pains to show that these two concepts are not identical. Causality in my definition is the postulate that one physical situation depends on the other, and causal research means the discovery of such dependence. This is still true in quantum physics, though the objects of observation for which a dependence is claimed are different. They are the probabilities of elementary events, not those single events.

Thus, we believe that there is no compelling evidence for interpreting Heisenberg’s relations as an indication of the rule of chance in the atomic and subatomic world, implying the failure of determinism in the microworld. Our present knowledge only permit us to interpret these relations as implying the presence of imprecision or lack of certainty in this domain. There is a strong possibility that in the future a causal theory of microworld would emerge. The resurgence of interest in 1990’s in Bohm’s theory and its extension to solve some problems in cosmology is indicative of the unhappiness of some eminent physicists with the standard quantum mechanics. As Gerard ’t Hooft, 1999’s Nobel Prize winner in physics, put it (’t Hooft 1997) :

Much more reasonable is the suspicion that the statistical element in our predictions will eventually disappears completely as soon as we know exactly the complete theory of all forces, the Theory of Everything. This implies that our present description involves variable features and forces which we do not (yet) know or understand … Anyway, for me, the hidden variable hypotheses is still the best way to ease my conscience about quantum mechanics.

To assume that our lack of success in giving a causal description of the atomic phenomena is an evidence for the rule of chance in nature is harmful scientifically and is against the dictation of logic. Because the denial of determinism is only one of the interpretations of quantum mechanics, without being its only interpretation. As Mario Bunge put it (Bunge 1979) :

Uncertainty in knowledge is far from being unequivocal sign of physical indeterminancy or haziness.

This uncertainty is simply an empirical uncertainty, and does not imply the failure of causality. It is good to stick to J. J. Thomson’s advice (Jaki 1992) :

The immeasurable of today may be the measurable of tomorrow … it is dangerous to base philosophy on the assumption that what I know not can never be a knowledge.

What the Copenhagen interpretation does is that it makes an unwarranted jump from an epistemological proposition to an ontological one. As S. Jaki put it (Jaki 1989) :

… the Copenhagen interpretation implies the fallacious inference from a purely operational to a strictly ontological proposition, namely, that an interaction that cannot be measured exactly cannot take place exactly.

The only thing we can logically say is that in one domain of science, our knowledge about causal laws is incomplete.

Causality in the Islamic Outlook

In the Islamic philosophy, the principle of causality is defined in the following way :

Every event requires a cause.

From this principle two corrolaries follow :

(i) Determinism. Every event has a sufficient cause, and with the presence of that cause, the event is present.

(ii) Uniformity of Nature. This means that similar causes entail similar effects. These corrolaries are inseparable from the principle of general causality, and any violation of them leads to the violation of the causality principle.

The validity of the principle of general causality is admitted in the Quran. Thus, e.g. the Quran talks frequently of the unchangeable patterns of God in the universe :

[Such has been] the course of God with respect to these who have gone before ; and you shall not find any change in the course of God. (33 : 62)

In the Quranic view, the cause of events in nature follow a certain measure, and every natural being has a definite and precise life span :

And there is not a thing but with Us are the treasures of it, and we do not send it down but in a definite measure (15 : 21)

In the Quran, one finds many cases in which the role of certain intermediary causes in the occurrence of some events are mentioned :

And God has sent down water from the cloud and there with given life to the earth after its death (16 : 55) And We sent down the winds fertilizing … (15 : 22)

The existence of certain patterns in nature means the existence of natural laws, and this in turn means that the principle of causality is valid. This, however, does not imply that events are totally independent of God. Rather, it implies that everything is realized by God’s will, but through definite secondary causes. Here we cite one example :

As for the good land, its vegetation springs forth by the permission of its Lord, and [as for] that which is inferior [its herbage] comes forth but scantly … (7 : 58)

This means that although God’s will is necessary for the growth of plants, the fertility of the land is also a condition. Some well-known Muslim theologians, particularly, of the Asharites School, used some verses of the Quran of the type

The commandment is wholly God’s … (7 : 54)

and some verses that indicate the occurrence of miracles, to refute the rule of causality in the physical world, and they attributed the occurrence of every event to God’s will. In their view the connection between what is usually believed to be a cause and what is believed to be an effect is not a necessary connection. Thus, e.g., it is not fire which causes the cotton to burn, rather, it is God who makes the cotton to burn and if God does not want, the fire will not burn the cotton (Al-Ghazali 1997). These theologians thought that the admittance of secondary causes would result in denying God’s power.

In refuting the Asharites view, Muslim philosophers argued in the following way :

(i) The coincidence of two causes operating on a single object is impossible if the relation of the two causes is horizontal. But, in a vertical system of causes one can attribute every event to God, because He gives it existence. But the emanation takes place through definite means.

(ii) In the case material beings, what is commonly called “cause” is not the efficient cause. Rather, it is an intermediary or secondary cause which prepares the ground for God’s bounty. Mulla-Sadra explains Muslim philosopher’s view (Sadr al-Din Shirazi 1981) :

Another group of philosophers and some elite among our Imamiah scholars say that objects vary in their acceptance of existence from the Origin. Some do not yield to existence unless another being precedes them, in the same way that accident should follow substance. Thus, the Creator, whose power is unlimited, grants the existence according to the possibilities through a particular order and in consideration of its various capabilities. Some come directly from Him, some through an intermediary or intermediaries. In the last form, nothing can come into existence unless its means and pre-requisites come into reality. God Himself is the Cause without a cause. Requirements for existence are not the result of deficiency in the Almighty’s power, but due to weakness in the receiver of emanation. How can one imagine any need or deficiency in the Creator, while means and ways are all originated from Him ? Therefore, the Glorious God does not need any help in the creation of anything.

In the case of miracles, we find an apparent breakdown of the laws of nature. But, this does not mean that the law is not valid or that the law of causality is violated. Because it is possible to make one law ineffective by the help of another law of nature (e.g. neutralizing the effect of gravitational force by electromagnetic force). The problem is that we do not know all laws of the universe.

After the advent of quantum theory in physics and the acceptance of Heisenberg’s uncertainty principle as signifying the rule of chance in the microworld, some Muslim scholars have revived the forsaken theory of the Asharites, and they have appealed to quantum theory to support their claim (Hardy 1993).

But, in refuting these claims modern Muslim philosophers have argued in the following way (Mutahhari 1373 H.) :

(i) The denial of the principle of causality in the microworld would mean defacing this principle in relation to the whole world, because causality holds the whole universe together. As Shabistari, the Persian mystic, put it :

If you remove a single piece out of its place the whole universe tumbles down

(ii)The generalization of the results of a limited number of experiments to general laws is only meaningful if the principle of causality holds. Planck elaborated on this view (Planck 1959) :

Of course it may be said that the law of causality is only after all a hypothesis. If it be a hypothesis, it is not a hypothesis like most of the others, but it is a fundamental hypothesis because it is the postulate which is necessary to hive sense and meaning to the application of all hypothesis in scientific research. This is because any hypothesis which indicates a definite rule presupposes the validity of the principle of causation.

(iii)The impossibility of prediction in atomic domain results from our ignorance about the deterministic laws governing the microworld. This could be due to our lack of necessary experimental tools or due to the immeasurability of the effects of the observer on the experiment. (iv) The denial of the principle of causality amounts to the denial of reasoning. Because a proof is the cause of our accepting the desired result, and if the tie between the proof and the result were non-essential, the proof could not end in the result. In this case nothing would be the result of a proof and any proof might lead to any result. In short, science has to accept the principle of causality in order that its existence could be meaningful.

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