Al-Ghazālī,
Causality, and Knowledge
ABSTRACT: Few passages in Arabic philosophy have
attracted as much attention as al-Ghazālī’s discussion of causality
in the seventeenth discussion of Tahāfut
al-Falāsifa, along with the response of Ibn Rushd (Averroës) in his Tahāfut al-Tahāfut. A question
often asked is to what extent al-Ghazālī can be called an
occasionalist; that is, whether he follows other Kalām thinkers in
restricting causal agency to God alone. What has not been thoroughly addressed
in previous studies is a question which al-Ghazālī and Ibn Rushd both
see as decisive in the seventeenth discussion: what theory of causality is
sufficient to explain human knowledge? In this paper I show that
al-Ghazālī’s and Ibn Rushd’s theories of causality are closely
related to their epistemologies. The difference between the two thinkers can be
briefly summarized as follows. For Ibn Rushd, the paradigm of human knowledge
is demonstrative science; for al-Ghazālī, in contrast, the paradigm
of human knowledge is (or at least includes) revelation. Yet both remain
committed to the possibility of Aristotelian science and its underlying
principles. Thus, I suggest that al-Ghazālī’s stance in the
seventeenth discussion sheds light on his critique of philosophy in the Tahāfut: namely, philosophy is not
inherently incoherent, but simply limited in scope. I also briefly compare this
position to that of Thomas Aquinas, in order to place the view in a more
familiar context.
Few passages in Arabic philosophy have
attracted as much attention as al-Ghazālī’s discussion of causality
in the seventeenth discussion of Tahāfut
al-Falāsifa, along with the response of Ibn Rushd (Averroës) in his Tahāfut
al-Tahāfut. A question
which has been addressed several times is to what extent al-Ghazālī
can be called an occasionalist: whether he here follows other Kalām
thinkers in restricting causal agency to God alone.[1]
What has not been addressed in studies of this text is a question which
al-Ghazālī and Ibn Rushd both see as decisive in the seventeenth
discussion: what theory of causality is sufficient to explain human knowledge?[2]
In this paper I will show that al-Ghazālī’s and Ibn Rushd’s theories
of causality are closely related to their epistemologies. The difference
between the two thinkers can be quickly summed up by saying that for Ibn Rushd
the paradigm of human knowledge is demonstrative science, whereas for
al-Ghazālī the paradigm of human knowledge is, or at least includes,
revelation. In closing I will suggest that al-Ghazālī’s commitment to
this paradigm sheds light on the guiding intent of his critique of philosophy
in the Tahāfut.
But before turning to the epistemic
aspect of the seventeenth discussion, let me say briefly what I take to be
al-Ghazālī’s basic position on causality. As others have noted, his
critique here imputes a very strong notion of causality to the philosophers:
namely that given the existence of a cause, the existence of its effect is
necessary.[3]
Al-Ghazālī holds that, on such a notion of causality, only God is a
cause. This is because, given the existence of miracles, and accepting the
proposition that God can do anything, no cause other than God can necessitate its effect. It is always
possible that God might will the expected effect not to proceed, or will an
entirely different effect to proceed. Al-Ghazālī defends this view
against both philosophers who claim that a natural cause, such as the fire
which causes the burning of cotton, is the sole and sufficient cause for its
effect, and against those who, like Ibn Sīnā
(Avicenna), would say
that there is a giver of forms in the celestial world which imposes form once a
sublunar cause has prepared some matter for that form. Against the first view,
al-Ghazālī gives the famous argument which has been compared to
Hume’s: observation of simultaneity does not prove that causation has occurred.
Against the latter view, al-Ghazālī says that if effects are brought
about by higher principles, they depend ultimately on God’s will, and God can
do anything except the absolutely impossible. Therefore, no effect proceeds
necessarily from its cause, unless the cause in question is God Himself.
But al-Ghazālī goes on to say,
in essence, that natural causes can be regarded as causes if we invoke a weaker
notion of causality. He admits that a natural cause has a nature which gives
rise to certain effects: fire, for instance, has a nature such that it burns
whatever is in contact with it. But this does not mean that fire is a necessary
cause, in the sense that the existence of fire in contact with cotton logically
entails the existence of burning cotton. The nature of fire itself, says
al-Ghazālī, derives from God, and God chooses whether or not this
nature will give rise to its normal effect or not. On al-Ghazālī’s
view, natural causes are only contingently causes -- their effects only proceed
if the true Agent who gave them their natures wishes it.[4]
Ibn Rushd was the first of many to see this position as an inconsistent
concession to the philosophers on al-Ghazālī’s part, because
al-Ghazālī seems at first to say that God is the only cause, and then
asserts that created things do have natures which lead them to cause their
effects. But al-Ghazālī’s view is not inconsistent: it merely sees
created natures as inherently contingent and provisional, relying on God’s
continued will for their efficacy and very existence.
Ibn Rushd’s response to al-Ghazālī
is based on the objection that if any form of occasionalism is accepted, there
is no possibility for human knowledge. He remarks that if what he perceives to
be al-Ghazālī’s denial of causality is accepted, ‘there is no fixed (thābit) knowledge of anything,’
because ‘certain (yaqīnī)
knowledge is the knowledge of the thing according to what it is in itself.’[5]
Here Ibn Rushd is tacitly relying on two principles of Aristotelianism. The
first is what we might call epistemic optimism: as an Aristotelian, Ibn Rushd
takes it for granted that humans have knowledge, so that if a theory of
causality is incompatible with our knowing things as they are, then this is
itself a sufficient refutation of that theory. The second is the principle that
things are only known demonstratively through their causes. This is of course a
basic tenet of medieval epistemology: elsewhere in Arabic philosophy, it is
used to argue for the impossibility of positive theology in the Liber de Causis, and it is the basis for
St. Thomas Aquinas’ notion of a propter
quid demonstration.[6]
For Ibn Rushd these two principles are the guidelines along which a theory of
causality must be developed. He says, for instance, that ‘if the things whose
causes are not perceived are unknown by nature and sought after, then what is
not unknown necessarily has perceived causes.’[7]
On the strength of the two principles, he is confident that he can rule out any
form of occasionalism.
The first thing that should be noted
about Ibn Rushd’s objection to al-Ghazālī here is that it does not
seem, at first, to be relevant. The objection assumes that al-Ghazālī
rejects the idea that things have natures, which are both the principles of
demonstrative knowledge and the principles of causality. By denying causality,
Ibn Rushd argues, al-Ghazālī has also rejected the possibility of
knowledge. But as we saw above, al-Ghazālī does not in fact
completely reject natures: he thinks a created thing has a created nature which
causes a proper effect, but that this nature and causation are always subject
to God’s will. Still, one can readily see how Ibn Rushd’s objection might be
adapted to meet this rather less occasionalistic view. If natures only possibly
give rise to their effects, then our knowledge of them is not necessary, but
only probable: natures must remain always the same if they are to be the
objects of demonstrative, scientific knowledge.[8]
Ibn Rushd alludes to this requirement when he remarks that knowledge based on
natures must be ‘fixed’ -- in other words, it must always be the case that
natures cause a proper effect, by the very definition of ‘nature.’[9]
This is one reason why Ibn Rushd insists that miracles, i.e. those cases in
which God does step in and disturb the natural course of causation, are not
even something we can rationally discuss. Supernatural events, as the very name
implies, are beyond any knowledge we can have of nature, and therefore are not
properly to be included in any discussion of causality or philosophy in
general.
It is a measure of how inapt is the
comparison so often made between al-Ghazālī and Hume that
al-Ghazālī both anticipates this objection and takes it seriously.
His goal is certainly not a kind of Humean skepticism; on the contrary, he is
just as committed as Ibn Rushd to Aristotelian epistemic optimism, and in a
sense he is even committed to the principle that knowledge is only through
causes. Thus al-Ghazālī himself raises the question of why miracles
do not prevent our knowledge of the empirical world, admitting that if they
did, a man who left a book in his home would have to say, ‘I do not know what
is in the house now, and the extent of what I know is only that I left a book
in the house, and perhaps now it is a horse.’[10]
Al-Ghazālī’s response to the objection is most intriguing: he
suggests that God continually creates in us the knowledge that He will not
perform these miracles. Thus the source of a man’s knowledge that, say, his
book is still in the house, is God Himself. Indeed, al-Ghazālī seems
to be contrasting the so-called ‘knowledge’ of experience, which only leads to
the habit of expecting given natures to cause given effects, with a certain
knowledge created in us by God. It should be noted here that it has been
questioned whether this passage represents al-Ghazālī’s own views --
the dispute turns on a point of translation.[11]
We need not, however, decide this question here, because even outside this
passage al-Ghazālī continues to propose that knowledge can be created
in us by God, both in the seventeenth discussion and elsewhere.[12]
A modern reader is likely, I think, to
reject al-Ghazālī’s solution as inadequate: a knowledge created by
God in a human hardly seems to qualify as knowledge in the proper sense at all.
This is in fact exactly the objection put by Ibn Rushd, who argues that one
only has knowledge if that knowledge has a direct relationship to the natural
cause that is known. Even assuming that God does create knowledge in a person,
that person is only said to know if the knowledge ‘is something dependent on
the nature of the existent, because the true is [when] one believes something
to be as it is in existence.’[13]
Thus our two authors are, at root, at odds with one another over the epistemic
question: what are the conditions for certain knowledge? For
al-Ghazālī, the habit of knowing brought about by experience is not
knowledge of what is necessary; only a knowledge produced by God is certain.
For Ibn Rushd, the situation is precisely reversed: if God creates a knowledge
in us, that knowledge is properly designated as knowledge only if it
corresponds to a real nature.
Modern intuitions about this question
notwithstanding, it must be admitted that al-Ghazālī’s view on
justification is perfectly consistent with his view on causality.
Al-Ghazālī admits that we do know that certain things will and will
not happen. But if causes are always contingent on God’s will in producing
their effects, then certain knowledge can only derive from the real source of
necessity in the causal relationship, namely God. Thus, as already remarked,
there is a sense in which al-Ghazālī would agree to the second
Aristotelian principle that knowledge is always through causes. But for him
this means that certain knowledge is always through God, because causality is
only through God. That this is really al-Ghazālī’s intent can be seen
from the fact that he puts knowledge of normal events on the same plane as the
special knowledge that is enjoyed by prophets. The knowledge that comes about
through the habitual course of nature is just as certain as the knowledge of a
prophet that there will be an exception in the course of nature, because both
sorts of knowledge are created by God.[14]
Thus it makes sense to say that, for al-Ghazālī, revelation or
prophesy is the paradigmatic form of knowledge for humans.
In the face of this view, Ibn Rushd’s
insistence on the Aristotelian definition of knowledge as perception in
conformity with a nature seems to be little more than begging the question.
This is because, as already mentioned, Ibn Rushd assumes that the supernatural
-- which for al-Ghazālī is fundamental -- is a subject which cannot
be understood nor even rationally discussed. Indeed, he chastises
al-Ghazālī repeatedly for bringing into the arguments of the Tahāfut things that should not be
disputed, lest the political function of religion be compromised. In the
seventeenth discussion, Ibn Rushd’s political argument against
al-Ghazālī is buttressed by an epistemological one: knowledge as such
has to do with natures, and therefore excludes supernatural causes and events.
Whether Ibn Rushd believes that miracles really do happen, or are only said to
happen for the sake of common believers, they will by definition not fall
within the realm of scientific, Aristotelian discourse: ‘it is necessary to say
about [the shari’a] that its
principles are divine matters transcending human intellects, and they must be
recognized without fail despite ignorance of their causes.’[15]
By itself, this assertion is question-begging because it does not address
possible counter-examples to the ‘philosophical’ paradigm of knowledge -- such
as miracles -- assuming in effect that ‘cause’ and ‘knowledge’ are simply terms
which do not apply to the supernatural.
Ibn Rushd does, however, have a more
elaborate response to give against the accusation of question-begging, because
of his own account of the importance of God for natural causes. The regularity
and predictability of natural causes, according to Ibn Rushd, is a testament to
God’s wisdom. Ibn Rushd can gain support for this view from the Qurān,
which he quotes explicitly: ‘And you will not find any alteration in the doings
(sunna) of God, and you will not find
any change in the doings of God.’[16]
Scientific knowledge is not, then, an affront to God’s power, but is only made
possible by God’s wisdom, which does not allow natures and therefore causal
relationships to change. The defense is deepened by Ibn Rushd’s allusion to
another doctrine he holds in the Tahāfut,
namely that God’s knowledge of things is the cause of their existence. Ibn
Rushd goes so far as to remark that God’s knowledge of natures must have the
same objects as our own, though in God’s case the relationship is causal, as
well as epistemic: ‘if we have knowledge of these possibles, then there is a
condition (hāl) in the possible
existents to which our knowledge pertains... and this is what the philosophers
designate as nature. Likewise, the knowledge of God is through the existents,
although [God’s knowledge] is their cause... and therefore it is necessary that
the existents come about in accordance with His knowledge.’[17] But the rejoinder open to
al-Ghazālī is clear: Ibn Rushd has here effectively raised scientific
knowledge to the level of divine knowledge; indeed, he has identified the two.
Thus it also becomes clear how much the paradigm of knowledge, for Ibn Rushd,
is that of natural science. But against al-Ghazālī, the view remains
question-begging. This is because Ibn Rushd assumes, rather than argues, that
divine wisdom and knowledge would be incompatible with a change in the course
of nature, whereas al-Ghazālī insists precisely that such changes are
possible.
Yet, does not Ibn Rushd have a legitimate
criticism of al-Ghazālī insofar as al-Ghazālī’s stance does
not allow for scientific knowledge at all? If al-Ghazālī holds to
some kind of epistemic optimism regarding natural science, this should remain a
problem for him. The answer to this question sheds light on
al-Ghazālī’s general attitude towards philosophy in the Tahāfut. Recall that
al-Ghazālī does, in fact, concede to the philosophers that there are
natures which give rise to effects. So he leaves room for scientific knowledge
of those natures (e.g. the knowledge that fire burns). What
al-Ghazālī denies is that such knowledge constitutes necessary knowledge
-- scientific discourse is partial, because it cannot establish whether a given
natural cause will be superseded by supernatural intervention. Thus
al-Ghazālī does not reject scientific or philosophical knowledge
altogether. What he does do is to show that it does not measure up to the
rather high standard the philosophers have set for themselves, namely that
knowledge be of relationships which are logically necessary.
This is, I would submit, representative
of al-Ghazālī’s strategy in the Tahāfut.
His goal is not to show the ‘incoherence’ of the philosophers, if this is taken
to mean that all of philosophy is incoherent. His goal is rather to show that
philosophy must be subsumed within an intellectual enterprise which includes
revelation -- and further, that revelation must be regarded as the most
superior kind of knowledge. The strategy of the Tahāfut is to show that philosophy, mostly as represented by
Ibn Sīnā, has overreached itself in a number of cases, reaching false
conclusions where reason should simply be recognized as inadequate. Thus in the
seventeenth discussion he remarks, regarding prophetic miracles, that ‘although
the extent of [the prophet’s] power is not determined in the intellect, there
is still no need to deny what is traditionally handed down and what revelation
mentions.’[18] Similarly, in the second discussion, taking
an approach like that of Maimonides, al-Ghazālī argues, ‘since it is
clear that we do not at all dismiss the permanence of the world from the
viewpoint of the intellect, but allow as possible the permanence and extinction
[of the world], we only know which possibility is really the case through revelation;
thus insight into this does not belong to reason.’[19]
Although al-Ghazālī
has traditionally been seen as an anti-rationalist, a mere opponent of
philosophy, our analysis of the seventeenth discussion suggests that his
attitude towards philosophy is both more subtle and less radical. The
al-Ghazālī of the Tahāfut
should be classed not with the anti-rationalists, but with those concerned to
keep philosophy in its proper place. For an analogous position in medieval
Europe, we need look no further than St. Thomas Aquinas. Though Aquinas is
usually considered to be far more of a rationalist than al-Ghazālī, a
Ghazālīan strategy of limiting the claims of philosophy can be found
in, for example, Question 12 of the Prima
Pars, where Aquinas argues that human reason by itself is unable to know
God, so that humans require the supernatural assistance of grace to achieve
their perfection. This is not to suggest that Aquinas’ view on the more
specific issue of causality is comparable to al-Ghazālī’s. Rather, it
is to suggest that, like Thomas, al-Ghazālī can be seen as
sympathetic to philosophy within its proper limits, even though he holds that
philosophy is not the highest paradigm of human knowledge.
I
have taken the liberty to rest this paper in the present form with footnotes in
lieu of endnotes, and corrections of minor typographical errors. (Muhammad
Hozien)
Source:
20 World Congress on Philosophy
[1] An argument against the occasionalist reading of al-Ghazālī is mounted in L.E. Goodman, “Did al-Ghazālī Deny Causality?,” Studia Islamica 47 (1978), pp. 83-120. A more occasionalist reading is given in Binyamin Abrahamov, “Al-Ghazālī’s Theory of Causality,” Studia Islamica 67 (1988), pp. 75-98, which also takes account of al-Ghazālī’s writings outside the Tahāfut. Ilai Alon, “Al-Ghazālī on Causality,” American Oriental Society Journal 100 (1980), pp. 397-405, argues that al-Ghazālī is trying to compromise between the theological and philosophical views. Another discussion can be found in Stephen Riker, “Al-Ghazālī on Necessary Causality,” The Monist 79 (1996), pp. 315-324.
[2] The only treatment of this issue I have found is Michael Marmura, “Ghazali and Demonstrative Science,” Journal of the History of Philosophy 3 (1965), pp. 183-204. Marmura raises some of the same topics I treat here, notably the tension between knowledge and occasionalism and the importance of the creation of knowledge by God. Marmura’s reading of al-Ghazālī is, however, more occasionalist than my own, so that we reach different conclusions about al-Ghazālī’s epistemology.
[3] See Goodman, pp. 84-5.
[4] Al-Ghazālī’s view is reminiscent of the one outlined by al-Kindī in his short treatise On the True Agent, in Al-Kindī, fī al-Falsafa al-Ûlā, in Risā’il al-Kindī al-Falsafiyya, ed. Abû Rīda (Cairo 1950), vol. 1, pp. 182-4, English translation in A. Altmann and S.M. Stern, Isaac Israeli (Westport, 1979), p. 68-9. In this treatise al-Kindī argues that though God is the true Agent, His effects are agents in a secondary, metaphorical sense, through their dependence on Him.
[5] Tahāfut al-Tahāfut li-Ibn Rushd, ed. Muhammad al-’Arīn, Dār al-Fikhr al-Lunbānī (Bairût, 1993), p. 296. (Hereafter Tahāfut.) English translation: Averroes’ Tahāfut Al-Tahāfut, trans. Simon Van Den Burgh, EJW Gibb Memorial Trust (Cambridge, 1954), p. 325. I read yaqīnī with Bouyges and al-’Arīn, rejecting Van Den Burgh’s reading of haqīqī (‘true’). In the notes to his translation, Van Den Burgh comments that he takes this to be an adequate refutation of al-Ghazālī (Van Den Burgh, vol. 2, p. 177). All translations in the paper are my own, though I have consulted Van Den Burgh’s translation and given page citations to it in the footnotes.
[6] Liber de Causis, Prop. 5: ‘And each thing is only known and described from its cause. And when the thing is only a cause and not an effect, it is not known by a prior cause, and is not described because it is higher than description, and speech does not reach it.’ (I translate from the Arabic.)
[7] Tahāfut, pp. 290-1. English translation p. 318.
[8] A similar point is made by Marmura, p. 200.
[9] Of course, this does not rule out that something else may impede a cause from bringing about its effect, as in the case where something is in contact fire but does not burn because it is covered with talc. Ibn Rushd addresses this point, remarking that the causation may be hindered (and is in this sense not necessary), but this does not mean fire has lost its ‘name and measure (hadd),’ i.e. the nature which makes it cause burning. (Tahāfut, p. 291. English translation p. 319.)
[10] Tahāfut, p.295. English translation p. 324.
[11] Goodman (p. 105) points out that the Van Den Burgh translation omits the words ‘fa laysa fī hādhāl-kalām illā tashnī’ mahd’ meaning ‘and in this statement is nothing but outright vilification.’ Goodman would translate the last two words as ‘...pure absurdity,’ so that al-Ghazālī would be calling the theologians’ position absurd. Marmura, defending a more occasionalist reading of al-Ghazālī, translates the same as ‘sheer vilification,’ referring to the philosophers. Marmura’s is clearly the better translation (tashnī’ being the verbal noun of ‘to vilify’), indicating that al-Ghazālī is in fact referring back to the criticism made by the philosophers. The passage is at Tahāfut, p. 296. See also Riker, p. 319.
[12] Tahāfut, p. 300, p. 258. English translation p. 330, p. 278.
[13] Tahāfut, p. 296. English translation, p. 325.
[14] Tahāfut, pp. 295-6. English translation, p. 324.
[15] Tahāfut, p. 294. English translation, p. 322.
[16] Qurān 35.43, cited at Tahāfut, p. 292. English translation, p. 320. See also Tahāfut, p. 302, English translation, p. 333.
[17] Tahāfut, p. 296. English translation, p. 325.
[18] Tahāfut, p. 298. English translation, p. 327.
[19] Tahāfut, p. 84. English translation, p. 70.