The
demonstrability of God’s existence in Summa theologiae of
Albert
the Great on the background of writings of Thomas Aquinas
Marcin Trepczyński
Abstract: The proofs of God’s existence are one
of the most important philosophical problems. But it seems that the crucial
issue concerns the possibility of proving existence of God.
The
problem of demonstrability of God’s existence is analyzed by St. Thomas Aquinas
in Summa contra gentiles and Summa theologiae. Both works are translated into
many languages (English and Polish are among them) and are well known to the
medievalists. Similar analysis is present in Summa theologiae of St. Albert the
Great, but this work is not translated yet. What is more, I have found only one
item in secondary literature which touches the problem of demonstrability and
proofs of God’s existence in this summa, namely: a book Albertus Magnus by
Ingrid CraemerRuegenberg.1 However,
it contains rather presentation of these proofs and – as far as the problem of
demonstrability is concerned – only a short record with Albert’s main solution.
I
think that it is worth to present precisely the approach to this problem of
Albert of Lauingen – one of the greatest thinkers of 13th century. What is more
a good idea is to compare his approach with Thomas Aquinas’ account. It may
facilitate to identify some common points and original solutions of these
contemporary thinkers, which is interesting especially when we keep in mind
that they belonged to the same Dominican order and that Thomas was at first
Albert’s disciple and later – his assistant. Recently a similar task was
undertaken by Gregory L. LaNave, who analyzed arguments for the existence of
God in Bonaventure to compare it with an approach of Aquinas.2
In
order to see what model of demonstrability a given thinker accepts, it is worth
to analyze also his arguments. The attitude to a given proof may reveal which
way of proving is reliable and which is not.
Thus,
in this article I intend to analyze Albert’s answer to the problem of
demonstrability of God’s existence and his presentation of the proofs of God’s
existence in Summa theologiae with references to his Commentary to the
Sentences of Peter Lombard and to the theological works of Thomas Aquinas,
especially his Summa theologiae.
1.
Context
Albert
the Great takes the issue of God’s existence (hereinafter: GE) in treatise 3 of
his Summa theologiae (hereinafter: ST).3 At
this stage we should note that the summa is his late and not finished work,
written after Aquinas’ death in 1274. However – according to Ferdinand van
Steenberghen4 – Albert does not take
Summa theologiae of Aquinas (hereinafter: STTA)5 into account. Apart from much earlier work
Commentary to the Sentences of Peter Lombard (hereinafter: Super Sent.),6 this is the only Albert’s work intended to
cover whole problems of theology and not only some of them.
Treatise
3 of ST is titled De cognoscibilitate, nominibilitate et demonstrabilitate Dei.
It is preceded by tr. 1 De scientia theologiae and the tr. 2 De frui, et uti,
et utentibus et fruentibus and followed by treatises about God’s attributes and
next about Saint Trinity. While the tr. 1 (on scientific status of revealed
theology and its methods) responses to the q. 1 of STTA, the topic
of the tr. 2 is absent in STTA and displays some influence of Peter
Lombard’s Sentences, which first book begins with the Augustine’s idea of
utendum et fruendum. In the tr. 3, which contains questions 13–18, the problem
of demonstrability of GE and proofs of GE are placed in the end (q. 17 and q.
18), after the problems of possibility to know God (qq. 13–15) and to name Him
(q. 16): so otherwise than in STTA, where the question about GE (q.
2) is the first one after a methodological q. 1 and precedes questions about
God’s essence (qq. 3–11), knowing Him (q. 12) and His names (q. 13).
The
topic of the q. 17 of ST is as follows: if it is demonstrable or self-evident
(known per se) that God exists. Let us note that both these problems are
considered in STTA (q. 2 a. 1 and a. 2), but in the reverse order,
and in Summa contra gentiles (hereinafter: SCG)7
(cc. 10–12), where the question is: if the demonstrability and the
self-evidence of GE are mutually exclusive and if the demonstrability of GE
should be excluded, as it is a revealed truth. For both thinkers it is very
important to resolve the problems of the demonstrability and self-evidence of
GE together. This is a consequence of Aristotelian theory of science which they
have accepted and which they applied to revealed theology. According to this
theory, in science, apart from definitions, we deal with: 1) self-evident first
principles and 2) statements which are obtained deductively. Thus, it seems
natural for them to examine if the statement about GE belongs to the first or
the second group and if one option excludes another.
The
q. 18 of ST is devoted to the topic of knowing God by natural reason and
divided into three chapters. The first one contains the proofs of GE. The
topics of the following chapters are: if one person may know God better than
another and is it possible to know Him by comprehension. In comparison with STTA
it may seem that in Aquinas’ work the problem of GE is much more exposed as a
first problem concerning God, while in ST this is just one of the problems of
knowledge about God and – what is more – placed together with two other in
question concerning the natural cognition of God, which concludes the treatise.
Nonetheless Albert’s composition of tr. 3 may be regarded as reasonable: at
first he considers what we can know about who is God; and when we already know
who is He – Albert analyzes before all if we can prove GE.
However,
it should be stressed that in ST Albert poses the problem of GE clearly and
explicitly, while he did not do it in Super Sent. Lombard’s Sentences have some
proofs of GE in the distinction 3 of the book 1. But the problem of GE is mixed
there with more general issue of knowing God, and especially the issue of God’s
uniqueness. This may explain why Albert in his commentary considers many
issues, but he does not pose the problem of GE separately, neither
demonstrability, nor proofs of GE. In the preface to this distinction he says
that Peter Lombard presents four rationes to prove that God exists and that He
is unique; in the first ratio Lombard proves GE, and in the following – that God
is incorporeal and immutable and that He is the highest Good and species omnium
specierum.8 Then, in the a. 1 Albert
considers whether philosophers knew that God is one, and in the a. 2: what they
knew about Him; the problem of GE and arguments for GE are present in these two
articles, but they do not seem to be crucial here. In the following articles he
formulates problems in the background of rationes presented by Lombard, but –
as he marked in the preface to d. 3 – they prove rather some other truths about
God, so the issue of GE is rather marginal. Whereas in ST Albert: plans
separate chapter for the proofs of GE, precedes it by the question of
demonstrability or self-evidence of GE and even presents Lombards rationes
which in Super Sent. he does not treat as arguments for GE but for something
else – as proofs of GE.
Finally,
let us add that also Aquinas does not pose a problem of the demonstrability of
GE in his Commentary to the Sentences (hereinafter: Super Sent.TA).9 He considers only problem of the possibility
to know God and the problem of self-evidence of GE there. His solutions can be
reduced to the question of capabilities of human intellect in relation to God’s
essence and existence.10
2.
Against demonstrability of God’s existence
It
should not be surprising that according to Albert GE is demonstrable. But the
main question is as follows: how is it possible to prove GE. In order to
understand it, it is very important to analyze precisely the objections which
Albert collected in the q. 17. He presents three arguments against
demonstrability of GE there.
The
first one is very short: “God exists” is an article of faith; article of faith
is something beyond the reason (supra rationem); but to be a subject of
demonstration something must be under the reason (sub ratione); so GE is not a
subject of demonstration.11 Similar
arguments are presented in STTA (q. 2, a. 2, arg. 1)12 and in SCG (c. 12, n. 1).13 Their common appearance reveals that this is
a basic problem in the context of demonstrability of GE and maybe even a
theological commonplace. However the same idea is formulated three times in
other words, what leads to a conclusion that there was no stiff and commonly
accepted formula, which Albert and Thomas might have only copied.
The
second argument has a similar nature. Everything, which is a subject of
demonstration, is perfectly comprehended by the intellect; but GE is not
perfectly comprehended by the intellect, so it is not a subject of
demonstration.14 The second premise
is based on a passage from the commentary of St. Gregory to Job 11, 7: “In
futuro reperietur omnipotens per speciem, sed non ad perfectum, quia essentia
eius a nullo plene videbitur”. It may seem that a similar argument we find in STTA
(q. 2, a. 2, arg. 2), and again there is the same idea, but differently
expressed.15 But this time, it is not
true. Albert says that we cannot comprehend that God exists (deum esse),
whereas Aquinas says that we do not know God’s essence (quid est), so we have
no medium term to build a demonstration (which is often a syllogism, in which
there must be a medium term, usually a definition). Thus, in this case the
argument presented by Albert may pretend to be original.
The
third argument is much longer and more complex.16
Albert discusses here some types of demonstrations to argue that none of them
is capable to prove GE. At the beginning Albert notes that the best
demonstration is based on the definition, that defines: what is something (quid)
or: by what cause (propter quid). In both cases it is impossible to apply such
demonstration to God, because we cannot say neither who God is nor point out
his cause (which – let us add – does not exist) and neither what is GE, nor
point its cause.
Next,
Albert agrees that, apart from the demonstration propter quid , there is a
demonstration quia, which has two kinds:
1)
by a remote cause or
2)
by an effect convertible with its cause.
He
refutes the first case, because there is no such a cause for God. If such a
remote cause were reduced to the close one, this would mean that God is not the
first cause (what is false). With regard to the second case, Albert says that
no effect is convertible and essential, which means that we cannot necessarily
conclude about the cause from the effect.
Finally,
he takes a demonstration by sign (per signum) into account, because St.
Augustine said: “omnia opera sua significationis suae sparsit indicia” (De
civitate Dei, lib. 11, 24). But to accept such a demonstration, we must be sure
that a given sign is convertible with its cause (like in the case of an effect)
and there is no such a sign, so we cannot use this kind of demonstration.
We
will not find such a complex argument in STTA. However, Thomas also
formulates an argument pointed at demonstrating from effects (q. 2, a. 2, arg.
3): GE may be demonstrated only from its effects, but they are not proportional
to their cause (they are finite, but their cause is infinite); cause cannot be
demonstrated by an effect which is not proportional to it, so GE is not
demonstrable.
Having
formulated these three arguments, Albert adds that we can imagine that someone
asserts that GE is not demonstrable, because it is self-evident. In order to
confirm self-evidence of GE he gives four arguments.
1. He quotes opinion of John of Damascus: “notitia
existendi deum omnibus per naturam inserta est”.
2. Then he refers to the Boethius’
definition of axiom – namely: some common truth, accepted by everybody who hear
it, because if he knows the meaning of terms used in such a sentence, he just
knows it; and everybody who knows what “God” and “to exist” mean, knows that
God exists.
3. Next, he quotes De caelo et mundo:
everybody agrees that God is in heaven; if He is somewhere, He does exist.
4. Finally, Albert says that if God is
principium intellegendi (what was said before), everybody who understands
something intellectually, accepts that God exists.
And
the objection to these four arguments is that – according do Ps. 14(13), 1 – “the
foolish man has said in his heart: there is no God”.17 Let us note that most of these arguments we
find in works of Aquinas. The first one – almost identical – in STTA
(q. 2, a. 1, arg. 1) and Super Sent.TA (lib. 1, d. 3, q. 1, a. 2,
arg. 1), and the second one – very similar – in STTA (q. 2, a. 1,
arg. 2) and in SCG (lib. 1, c. 10, n. 4). Whereas the fourth one we can find in
SCG (lib. 1, c. 10, n. 6) and Super Sent.TA (lib. 1, d. 3, q. 1, a.
2, arg. 2). In contrarium to these arguments is the same in STTA (q.
2, a. 1, s.c.) and Super Sent.TA (lib. 1, d. 3, q. 1, a. 2, s.c. 1).
It may mean, that apart from the third one, Albert collected rather commonly
known arguments for the discussed thesis. We may also point out that in Thomas’
writings there are at least three other arguments: from existence of truth,
which is God Himself (STTA, q. 2, a. 1, arg. 3), from the thesis
that every human tends to God (SCG, lib. 1, c. 10, n. 5), and the famous
ontological proof of Anselm of Canterbury (SCG, lib. 1, c. 10, n. 3; Super
Sent.TA, lib. 1, d. 3, q. 1, a. 2, arg. 2). And in Super Sent.TA
there is an original sed contra, that even philosophers demonstrated GE, so it
is not self-evident (lib. 1, d. 3, q. 1, a. 2, s.c. 2).
All
objections presented in the above arguments reveal some important worries about
the demonstrability of GE. Let us sum them up:
1. It may be impossible to demonstrate GE,
because human reason and intellect are not capable to comprehend God and His
existence, while it is necessary if we want to make them subjects of
demonstration.
2. None of possible kinds of demonstration
is capable to be used as a proof of GE.
3. It seems that GE is self-evident, so it
is not demonstrable.
The
third problem is not very troublesome; it seems that self-evidence does not
necessarily exclude demonstrability, although this would be some some
superfluum, as noted Aquinas in SCG (lib. 1, c. 10, n. 1). Whereas the first
and especially the second are really serious.
The
most important in the analyzed fragments is that Albert presents main kinds of
demonstration to check if some of them can be used to prove GE. In this way he
shows that such a proof must meet a very high standard of demonstration and
produce a conclusion which is necessary.
3.
God’s existence is demonstrable
Although
the demonstrability of GE is a topic of the q. 17 of ST, Albert reveals some
important information in this matter earlier – in the c. 1 of the q. 14. He
states there that from natural things we can positively know about God only
that He exists. But who He is – we could know only infinitely, which is
impossible.18 But we can know who He
is not, so on the way of negation or privation (privativo). The opinion that by
the natural reason we can know that God exists, but we cannot comprehend Him,
was common in 13th century. However, Albert strengthens it by the authority of
John of Damascus, who said: “Quoniam igitur est quidem deus, manifestum est;
quid vero est secundum substantiam et naturam, incomprehensibile est hoc omnino
et ignotum”.
Then
Albert records that according to Cicero Aristotle proved GE and presents the
first proof of GE (taken from Cicero’s De natura deorum, l. 2, c. 6, n. 17). It
is based on the analogy with a beautiful empty house which – as everybody
rightly assumes – must have had an architect. The conclusion is that nothing in
the world can be a cause of the world, but the world needs someone wise, whose
virtues exceed every world’s virtue; in this way it is possible to know God
from the natural things. Finally, he says that this is the meaning of the
passage from Rom. 1, 20: “Invisibilia dei per ea quae facta sunt, intellecta
conspiciuntur”.19
To
sum up, Albert does not use here a term demonstratio, but he accepts that we
can know that God exists on the basis of created world. He records: 1) an opinion
of John of Damascus, who asserts that GE is obvious or clear (manifestum), 2) a
proof or an argument and 3) a passage from Holy Scripture which confirms the
accepted thesis. On this basis he does not judge yet, if GE is per se notum or
demonstrabile.
This
problem is finally resolved in the q. 17. Having presented objections, Albert
confronts them with the passage from Rom. 1, 20 and concludes that GE is
demonstrable per effectum. And in the solution he shows that we can discern
such kinds of demonstration:
1. in a large or common way (large sive
communiter) – when we use any proof (ostensio), by internal or external
premises (sive in se sive in alio);
2. in a strict or proper way (stricte sive
proprie) – a syllogism in which we conclude by essential and convertible medium
term, no matter if this medium term is a cause, an effect or any other
equivalent, as for example a sign; it has two kinds:
2.1 demonstratio ostensiva,
2.2 demonstratio ad impossibile. Albert
states that in the case of demon stratio ostensiva (2.1) it is impossible to
demonstrate GE, and he confirms the strongest objection – arg.
3. This means that we cannot use a strict
syllogism to prove GE per effectum. As far as other cases are concerned, Albert
allows to demonstrate GE. In the case of ostensio (1) he even says that such a
demonstration is easy. And to illustrate how we can demonstrate GE ad
impossibile (2.2) he says that – according to Aristotle’s positions against
Heraclitus in book IV of Metaphysics – if we assumed that God does not exist,
there would result many impossible conclusions.20
Hence,
the outcome is:
Kind
of demonstration Demonstrability
of GE
Demonstration in the
common way (ostensio) (1) +
Demonstration demonstratio ostensiva (2.1) -
in the proper way demonstratio ad impossibile (2.2) +
In
this light let us see the answers to the objections. According to Albert the
Great, the sentence “God exists” is not properly an article of faith, but
rather an antecedent to every article (similarly in STTA, q. 2, a.
2, ad 1). The second argument is accepted – because the perfect comprehension
is impossible, GE is not demonstrable ostensive (2.1). Also the third argument
is accepted. However, Albert stresses that from the objections recorded in this
argument does not follow that GE is not demonstrable in another way and he
admits that there is such a way. With regard to signs, they cannot be a basis
for a demonstration, but it is possible to use them in a “sufficient persuasion”.21 And as far as the contrary argument, in which
Albert quotes the passage from Rom. 1, 20, is concerned, those “invisible
things of God” can be seen through “what had been made”, but not by
demonstratio ostensiva, but by ostensio “sufficient for persuasion”.22 Finally, Albert resolves the problem of self-evidence.
He makes some distinctions and in majority of cases states that they do not
disturb to demonstrate GE.23 However,
it is interesting that he seems to accept almost all arguments for self-evidence
of GE (except the last one). This problem is resolved completely differently by
Aquinas, who states that GE is self-evident secundum se, but for us (quoad nos)
it is not, so it needs a demonstration (STTA, q. 2, a. 1, co.;
similarly SCG, lib. 1, c. 11, n. 1, and Super Sent.TA, lib. 1, d. 3,
q. 1, a. 2, co.). The most important information given by Albert in his
solution and his answers are:
1. that GE is demonstrable,
2. that strict syllogistic demonstration
of GE per effectum is refuted,
3. that the way shown in Rom. 1, 20 is
sufficient only for persuasion.
The
second information may seem contrary to what Aquinas has written in STTA.
In the corpus of q. 2 a. 2 Thomas discerns two kinds of demonstration:
propter
quid, which is by what is objectively prior ( per priora simpliciter), and
quia,
which is per effectum, so by this what is prior only for us (quoad nos).
Next,
he states that from any effect we can demonstrate that its cause exists,
because if an effect depends on some cause and we assume that there is the
effect, it is necessary that there was its cause. And he concludes that GE is
demonstrable per effectum.24 If
Thomas says here about the demonstration which Albert calls demonstratio
ostensiva, it means that their opinions are contrary. A possible explanation is
that in some cases (like GE) Thomas accepts that an effect may be convertible
with an existence of its cause.
But
it is possible that Aquinas does not have in mind such a strict syllogistic
demonstration here. Let us add that according to Albert’s description, such a
demonstration is limited to the categorical syllogism (because it has to have a
medium term), but it cannot have a form of hypothetical syllogism. If these
assumptions are right, we could admit that Aquinas thinks about a kind of
demonstration which Albert called ostensio, and then they agree.
To
resolve this problem we need to see the examples of proofs of GE which Albert
accepted and compare them with those presented by Thomas.
Finally,
the third of these most important information may raise serious doubts. Albert
says that the thesis from Rom. 1, 20 is about what we see by ostensio which is “sufficient
for persuasion”. Does it mean that he admits that some of proofs of GE may have
such a status and do not meet the standard of demonstration? I am afraid that
if Albert does not point that a given argument is a demonstration, such a doubt
is justified. However, we may assume something opposite – that he considered
the question of demonstrability of GE so precisely that he will point it, if
some argument or proof will have – in his opinion – a lower status, like
ostensio which is sufficient for persuasion. Also in this case, in order to be
convinced of this, we should analyze the examples of proofs of GE collected by
Albert.
4.
Demonstrability and seven proofs
In
the q. 18 c. 1 of ST Albert presents proofs of GE. He calls them “the ways
(viae) by which natural philosophers by the means of reason had known that God
exists” (proem.). Five (or six) of these proofs are based on the text of the d.
3 of Peter Lombard’s Sentences and come from St. Ambrose or St. Augustine.
Next, Albert adds a proof taken from Aristotle and the last one – from
Boethius. Afterwards, in the same chapter, he also adds two ways to know God’s
unity and trinity, which seems strange in the context of the topic of this
chapter.
It
is interesting that Albert, without any comment, decides to present proofs taken
from the Sentences. As it was already said, Albert states clearly the problem of
GE in this question, whereas – as was also already said – Peter Lombard refers
to the question of GE only in the first proof and the other proofs concern
God’s attributes. This may mean that Albert reworked these proofs to use them
in the context of GE, however, it unfortunately seems that he did not succeed
in every case.
The
first proof, taken from St. Ambrose, is based on the notion of efficient cause
and is similar to this presented by Albert in the q. 14. After quoting Lombard
Albert tries to build his own argumentation:
1. in all parts is made this, what must be
made in the whole;
2. nothing is its own maker (factiva sui)
(otherwise: potentia = actum, and: there is something and there is not at
once); hence:
3. as a part has a particular efficient cause,
the whole has a universal efficient cause, but it is not a maker of itself;
4. so no creature can be a maker of the
world (factor mundi ), hence such a maker is not a creature;
5. so he is creator (creator), so: God.
Albert records here a similar proof of Augustine and John Chrysostom about
verbum which is principium.25
The
second proof is attributed to Augustine (De Civitate Dei). Albert rather only
paraphrases what he has found in Lombard’s version and does not add much. The
main argumentation may look similar to the Aristotelian proof from movement:
1. everything changes, it changes location
or it starts to be,
2. and everything is in potentia to this,
what changes or moves it;
3. but universaliter motivum and
universaliter activum can be only God.26
However,
it is not clear if this proof is intended to prove GE or rather to show, what
we know about God due to the operation of “ablation”.
The
third proof also comes from Augustine and again concerns the notion of
efficient cause, so it is similar to the first one. However it seems extremely
weak:
1. universaliter factivum cannot be made
by something else;
2. everyone assumes that God is
universaliter factivum;
3. so He is not made by anything else, but
He makes everything. Albert admits that this “way” certifies only that there is
some maker of everything and this is God.27
The
fourth proof (also from Augustine) is rather intended to show, who God is, than
to prove His existence. The conclusion of this proof is: He is substantia
intelligibilis intelligens and the cause of every intelligence, which makes
everything by intellect.28
The
fifth and the last proof taken from Lombard bases on the passage from Rom. 1,
20 and some Augustine’s comments. But again it does not seem to prove GE, but
some God’s attributes by which He is supereminent in comparison to creatures.29
The
sixth proof Albert borrows from Aristotle – this is the famous proof from
movement, taken from book VIII of Physics. In short:
1. first mover (motor primus) cannot be
moved by anything else;
2. what is a mover cannot move or be moved
unless by first mover;
3. if first mover stops moving, everything
stops;
4. we see that nothing stops and many
things move, so: 5) it is necessary that there is a first mover, which is a
moving and immobile act.30
The
seventh and the last proof comes from Boethius’ De hebdomadibus. In short:
1. it is self-evident that everything what
has existence (esse) and what is this (hoc) – has it from another this ;
2. everything that is in the world has
existence and has that is this, so it has it from some another this;
3. from a determined cause it has that it
is this;
4. so it has not its essence from the same
cause;
5. every second cause is determined;
6. so it has that it is this from no
second cause;
7. there is some cause of existence in
made beings;
8. it may be only a first or a second
cause;
9. so it must be that caused existence is
from the first cause and we call it God.31
This
set of proofs or “ways” differs much from the famous five ways of Aquinas (STTA,
q. 2, a. 3, co.). Albert wanted only to report the common proofs without an
attempt to formulate some original and really strong proof, while Thomas –
although he based on the whole philosophical tradition – tried in STTA
to choose really strong and order them well. Moreover, it seems that Albert in
ST is still under strong influence of Lombard’s Sentences; he is not able to
leave some of the Lombard’s proofs or correct some of them in his own way. The
result is that, despite the task stated in proemium, some of these proofs do
not prove GE and others are really weak. Only the Aristotelian and Boethian
have some strength, however they are not perfectly ordered. Four of them are
similar to those presented by Aquinas: two from efficient cause, Aristotelian
(first mover) and the one concerning gradation which leads to perfection. But
they are far from well-ordered and clear proofs from STTA. We should
note that in ST there is no proof concerning possibility or necessity, what is
present in STTA. There is also no ontological proof. Here Albert is
of the same opinion as Thomas, and consequently accepts only proofs based on
sensual observation – per effectum.
What
is most important, Albert’s presentation unfortunately left many doubts arisen
on the basis of q. 17. The cause lies in the weakness of these proofs and in
the fact that the fifth proof uses the passage from Rom 1, 20 which – according
to Albert – concerns ostensio sufficient for persuasion. Thus, what status have
these proofs? Are they kinds of demonstration or just a persuasive argument? If
they were constructed like in STTA, we could argue that Albert
really conducts demonstration and the presented ways are really proofs.
However, the first, the sixth and the seventh still may pretend to be examples
of demonstration and not only a persuasive argument.
If
we remember that a proof from the first mover is present also in STTA
and if we assume that at least this proof is a kind of demonstration, then we
have a basis to say that for sure Albert would recognize Aquinas’ arguments as
a demonstration, but not as demonstratio ostensiva, but as ostensio. If so,
although Thomas accepts demonstratio ‘quia’ to prove GE per effectum, both
Dominicans agree.
Finally,
we should remind that Albert noted that one of strict kinds of demonstration is
demonstratio ad impossible and said that this was a certain way to prove GE.
However he did not present any proof of this kind in ST. It is not clear why he
did not do it.
5.
Conclusions
The
above analysis allows the following conclusions.
1. Albert in ST states and resolves the
problem of demonstrability of GE.
2. He states there that GE is
demonstrable, but not in every form of demonstration. It is impossible to
demonstrate GE ostensively in a “strict” way which he calls demonstratione
ostensiva, so through the syllogism (perhaps he has in mind only categorical
syllogism) in which we conclude by essential and convertible medium term (which
can be a cause, an effect or any other equivalent, as for example a sign).
It
is possible to demonstrate GE:
(1)
in the form of demonstration in a “larger” or “common” way, which Albert calls
just ostensio, so any logically correct proof, or
(2)
in the form of kind of demonstration in the strict way which is demonstratio ad
impossibile. Albert admits that by ostensio it is even “easy” to prove GE.
3. According to Albert GE is in the same
time self-evident, but it does not mean that GE should not be demonstrated.
4. Albert states in ST that GE is not
perfectly comprehensible for human intellect, so we cannot use it as a medium
term in syllogisms. He also sketches there the highest standards for necessary
demonstration (demonstratio ostensiva).
5. Although we may find some arguments and
objections from ST in Aquinas’ writings, in many points the solutions of Albert
and Thomas differ very much. This may indicate their independence and originality,
but at this stage this is only a hypothesis. There is a great difference in
solutions concerning the question of selfevidence of GE and demonstrability of
GE. However, the analysis of proofs of GE, presented by Albert, gives a basis
to argue that in this last case their views are coherent.
6. Albert recognize in ST the main
argument for demonstrability of GE: “Invisibilia dei per ea quae facta sunt,
intellecta conspiciuntur” (Rom. 1, 20) as ostensio “sufficient for persuasion”.
On this basis arises a doubt, which proofs or arguments meet the standard of
demonstration and thus provide necessary conclusions, and which have only a
persuasive significance.
7. Albert in ST poses independently the
problem of GE and in this context he provides seven proofs. These are “ways by
which natural philosophers by the means of reason had known that God exists”,
so they do not tend to be original. Five of them come from the Sentences of
Peter Lombard, where they do not prove GE except the first one, but rather they
prove God’s attributes. Although Albert in ST states clearly the question of
GE, it seems that he remains under the influence of Sentences and fails in
presenting wellordered proofs of GE. Only one of them and two additional
(Aristotelian and Boethian) pretend to be correct demonstrations. The rest has
definitely lower status and should not be regarded as examples of
demonstration.
8. It seems strange that, first, Albert
lists demonstratio ad impossible as a way to prove GE, but next – he does not
present any such proof, although it would bring a necessary conclusion.
Demonstrability
of God’s existence is one of most important philosophical problems. It was
discussed by Albert the Great in his Summa theologiae. However I did not find
any work which analyzed how he did it and only one work which mentioned this
problem. This topic seems crucial in philosophy, because it opens the way for
proving God’s existence. It was obvious for Thomas Aquinas – also in his Summa
theologia the issue of demonstrability of God’s existence precedes the famous “five
ways”. This is why in this paper I analyze Albert’s discussion about
demonstrability of God’s existence in his most mature, not finished work Summa
theologiae. At every step I compare it with parallel passages from theological
works of Thomas Aquinas to trace down common points and original solutions of
both thinkers. The outcome of this analysis is to some extent surprising.
Although Albert and Thomas sometimes formulate similar arguments, it happens that
their answers are completely different. For example Albert states that God’s
existence is generally self-evident, whereas Thomas – that for us (quoad nos)
it is not. What is more, Aquinas says that we can demonstrate God’s existence
from the effect (per effectum), while Albert, who distinguish three kinds of
demonstration, seems to refute such a possibility and allows only demonstration
ad impossible and less strict demonstrations. Although it is possible to agree
their views in this case, we finally do not know if they really would agree.
Some more information concerning the discussed problem we obtain from Albert’s
presentation of proofs of God’s existence. However it differs a lot from
Aquinas’ presentation in his Summa theologiae.
Moreover,
on the background of Albert’s earlier statements it is doubtful if he treats
all collected proofs as correct demonstrations which provide necessary
conclusions. Albert’s discussion about demonstrability of God’s existence
leaves many questions. However it seems interesting, inspiring and leads to
rethink again Thomas’ positions.
1. I. CraemerRuegenberg, Albertus Magnus,
ed. H. Anzulewicz, Leipzig 2005, Benno Verlag, s. 61– 68 (caption:
Gottesbeweise). Let us note that the topic of demonstrability of God’s
existence in Albert’s writings was not analyzed even in volumes published on
the occasion of 800 annuary of Albert’s death: Albertus Magnus – Doctor
Universalis 1280–1980, ed. G. Meyer, A. Zimmerman, Mainz 1980; Albertus Magnus
and the Sciences. Commemorative Essays, ed. J.A. Weisheipl, Toronto 1980.
2. G.F. LaNave, Bonaventure’s arguments
for the existence of God and the “independent” De Deo uno, “The Thomist” 74
(2010), s. 5784, esp. 81–84. At the beginning he notes that “it has been
customary and indeed almost inevitable, for Bonaventure to be read in
comparison with his Dominican contemporary Thomas Aquinas” (s. 57).
3. Albert the Great, Summa theologiae sive
de mirabili scientia dei. I use the text of editio Coloniensis in: Alberti
Magni Opera Omnia, t. 34, part 1, ed. D. Siedler et. al., Münster 1978. Because
this work is crucial here, in this case I will give the numbers of pages and
verses of quoted passages.
4. F. van Steenbergen, Philosophie au
XIIIe s., Paris 1966, in the Polish edition: Filozofia w wieku XIII, trans. I.
Zieliński, Lublin 2005, s. 236.
5. Thomas Aquinas, Summa theologiae. I
use: textum Leoninum, Rome 1888.
6. Albert the Great, Super IV libros
Sententiarum, in: Opera omnia, t. 25–30, ed. A. Borgnet, Paris, 1893–1894.
7. Thomas Aquinas, Summa contra Gentiles.
I use: Textum Leoninum, Torino 1961.
8. Super Sent., I, d. 3, 90b. In the text
of the Sentences Lombard concludes then that on this basis God is also:
conditor aeternus, omnipotens, sapiens and bonus, and adds that all these prove
that God is one ; Petrus Lombardus, Sententiarum libri quattuor, PL, lib. I, d.
3, c. 5.
9. Thomas Aquinas, Scriptum super
Sententiis. I use the edition: Parma 1856.
10. Super Sent.TA, lib. 1, d. 3,
q. 1, aa. 1–2.
11. „Deum enim esse articulus est fidei;
articulus autem supra rationem est; quod autem demonstratur, sub ratione est;
ergo deum esse non demonstratur” (ST, q. 17, arg. 1, p. 83, v. 71–73).
12. „(...) Deum enim esse est articulus
fidei. Sed ea quae sunt fidei, non sunt demonstrabilia, quia demonstratio facit
scire, fides autem de non apparentibus est, ut patet per apostolum, ad Hebr.
XI. Ergo Deum esse non est demonstrabile”.
13. „(...) Dicunt enim quod Deum esse non
potest per rationem inveniri, sed per solam viam fidei et revelationis est
acceptum”.
14. „Adhuc, omne quod demonstratur perfecto
intellectu comprehenditur; deum esse perfecto intellectu non comprehenditur;
ergo non demonstratur” (ST, q. 17, arg. 2, s. 83, v. 74–76).
15. „Praeterea, medium demonstrationis est
quod quid est. Sed de Deo non possumus scire quid est, sed solum quid non est,
ut dicit Damascenus. Ergo non possumus demonstrare Deum esse”.
16. This argument may be interpreted as
three separate arguments, but I prefer to treat it as one, although triple. ST,
q. 17, arg. 3, s. 84, v. 3–36. The chosen passages: „Adhuc, medium in
demonstratione potissima dicit ‚quid’ et ‚propter quid’; ‚quid’ autem et
‚propter quid’ nec habet deus nec habere potest... (…) Si enim demonstraretur
esse de deo, oportet, quod esset medium diffinite dicens ‚quid’ et ‚propter
quid’ vel esse divini vel dei, secundum duas opiniones... (…). Neutrum autem in
deo diffinibile est diffinitione dicente ‚quid’ et ‚propter quid’. (…)
Demonstratio ‚quia’ non fit nisi duobus modis, scilicet per causam remotam vel
per effectum convertibilem. Per causam enim remotam non potest demonstrari,
quia talem non habet; causa enim remota per coartationem fit proxima; et si
deus vel esse dei talem causam haberet, sequeretur, quod ipse non esset causa
prima, quod falsum est. Similiter per effectum non potest demonstrari; nullum
habet effectum convertibilem et essentialem. (…) Demonstratio per signum, si
debeat certificare sicut vera demonstratio, oportet quod fiat per signum
convertibile cum causa; nullum tale signum est in effectibus dei. (...)”.
17. Tamże, v. 42–74.
18. Por. Super Sent.TA, lib. 1,
d. 3, q. 1, a. 1, arg. 4.
19. ST, tr. 3, q. 14, c. 1, s. 51, v.
17–71.
20. ST, tr. 3, q. 17, s. 84, v. 75 – s. 85,
v. 3. The chosen fragments: „(...) Communiter demonstratur, quod quacumque
ostensione ostenditur, sive in se sive in alio. Et hoc modo demonstrabile est
deum esse. (…) Et hoco modo facile demonstratur deum esse. Stricte autem vel
proprie dicitur demonstratio syllogismus, per medium essentiale et convertibile
concludens, sive hoc medium sit causa sive effectus sive alteri alteri illorum
aequivalens ut signum convertibile. Et heac demonstratio duplex est, ostensiva
scilicet et ad impossibile. Dicimus ergo, quod demonstratione ostensiva non est
demonstrabile deum esse, sicut bene probatum est obiciendo. Sed demonstratione
ad impossibile demonstrabile est deum esse... (…)”.
21. ST, tr. 3, q. 17, s. 85, vv. 4–32.
22. ST, tr. 3, q. 17, s. 85, vv. 33–37: „Ad
id quod obicitur in contrarium, dicendum quod‚ invisibili dei per ea quae facta
sunt, intellecta conspiciuntur conspectione ostensionis sufficientis ad
persuasionem et non conspectione demonstrationis ostensive”.
23. Albert discerns self-evidence: 1) ex
parte noscentis, 2) ex parte noscibilis and 3) propositio which is know when we
know its terms, and this third kind has also three kinds: a) known by anybody
who hears it, b) known by all wise men, c) known by wise men who know who is
God, what is esse and that God is a principle and source of esse. In the cases
1 and 2 Albert points that from selfevidence does not follow that there cannot
be some rational proof, and in the case and 3b he says that a wise man proofs a
self-evident truth. Por. ST, tr. 3, q. 17, s. 85, vv. 38–68.
24. „Respondeo dicendum quod duplex est
demonstratio. Una quae est per causam, et dicitur propter quid, et haec est per
priora simpliciter. Alia est per effectum, et dicitur demonstratio quia, et
haec est per ea quae sunt priora quoad nos, cum enim effectus aliquis nobis est
manifestior quam sua causa, per effectum procedimus ad cognitionem causae. Ex
quolibet autem effectu potest demonstrari propriam causam eius esse (si tamen
eius effectus sint magis noti quoad nos), quia, cum effectus dependeant a
causa, posito effectu necesse est causam praeexistere. Unde Deum esse, secundum
quod non est per se notum quoad nos, demonstrabile est per effectus nobis notos”.
25. ST, tr. 3, q. 18, s. 86, vv. 12–44.
26. Tamże, s. 86, vv. 45–63.
27. Tamże, s. 86, vv. 64–70.
28. Tamże, s. 87, vv. 1–23.
29. Tamże, s. 87, vv. 24–57.
30. Tamże, s. 87, vv. 58–81.
31. Tamże, s. 87, v. 82 – s. 88, v. 13.
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