Reason and Faith


St. Thomas Aquinas
John Duns Scotus
 The question of faith and reason is thought in many cases
to be a problem of consistency among the dictates of reason
and those of faith and is formulated in terms of the
reliability of the many ways of justifying true belief.
Thus the qualm `Which is more reliable?' may change into a
doubt and eventually it is asked whether faith justifies

"Another type of claim to knowledge ... is faith. The same
difficulty that plagued the claims to knowledge by
intuition and revelation occurs here ... Thus sense
experience and reasoning, not faith, are the basis for the
claim of reliability... Indeed, it seems too obvious to
mention that when people appeal solely to faith as a way of
knowing, they do so because there is no evidence that what
they say is true ... "1
The above explanation taken from the finale of a section
discussing the sources of knowledge in a somehow outdated
textbook of philosophical analysis written in our century
is not in essence very far removed from the debates which
had taken place among medieval philosophers after the
twelve hundreds. The former may be more straigtforward in
rejecting faith as knowledge. But the latter too must have
comprised strong arguments against the reliability of
faith. Scotus formulates several of these arguments, which
reject the reliability of faith after a cursory
examination, in the first question of the Prologus to the
Ordinatio.2 In the course of ScotusÙ evaluation of the
controversy for and against the reliability of faith not
only do we discover the familiar qualms about faith in
comparison to sense-experience and the employment of
reason, but also we learn about the two distinct manners in
which Thomas Aquinas and John Duns Scotus were teaching in
favor of faith. The first question of Scotus' prologue to
the Ordinatio develops the issue of faith from various
perspectives. There are two questions which concern us. The
first question is about the reliability of faith in the
eyes of Scotus and Thomas. The other question is about the
difference, if any, between their thoughts on faith and
reason. As to the first question, it is quite clear that
both doctors proclaim the reliability of faith. As to the
second question, the answer is that there are differences
between the two teachings. Scotus states that there can not
be conclusive arguments in philosophy pro the reliability
of faith; all that can be done is to use persuasive
arguments from faith and at the same time to keep making
the effort of showing with strictly philosophical reasoning
that the arguments of the philosophers for the reliability
of the intellect, the senses or some other source is not as
foolproof as one would like to have them. (n. 12, nn.

Aquinas on the one hand holds that faith is reliable, but
on the other hand he maintains an Aristotelian theory of
knowledge. All knowledge is derived from the senses. The
human intellect can not operate without phantasms or
sensory data. And yet, the human intellect is not dependent
on a corporeal organ for its proper operations and the
human soul is incorruptible. There is one human soul for
each human person and that soul is the form or act of the
human body. It is the business of the intellect to know
natures and essences in their common or absoluteley
considered natures. But still, a knowledge both of itself
and of particular things is possible for the human
intellect. The final cause for mankind is salvation and
felicity in beholding God. It will be presented below that
Aquinas leaves an allowance for philosophers who interpret
Aristotelian philosophy as a philosophy devoid of sympathy
for faith. He suggests that the end of man may also be
known solely in philosophy without recourse to faith. 
(II) The views of the two doctors
In the critical edition of the Ordinatio, St. Thomas is
cited by the editors in the footnotes to the text. In the
controversy between the philosophers and the theologians,
philosophers put forward three important arguments.
Philosophers uphold the perfection of nature. Theologians
recognize the necessity of divine grace and perfection. The
Saint is mentioned in relation to the second argument of
the philosophers in connection with Aristotle who divides
the speculative sciences into mathematics, physics and
metaphysics. It seems that Aristotle proves the
impossibility of there being more speculative sciences
because - in those three, both as it is in itself and in
asmuch as it is in every part, the whole of being is
thoroughly taken into account; by a similar argument there
can not be more practical sciences than those acquired by
mankind. (n. 8) 

St. Thomas is also mentioned in relation to a certain
argument, again from the side of the philosophers, against
the need for faith. The argument again takes off from
Aristotle: `Nature never leaves out what is necessary'; if
it is not deficient in imperfect faculties, i.e., the
senses, much less will it be deficient in the intellect.
(n. 2) In other words, if supernatural aid is not needed by
the senses for apprehending their objects, neither will it
be needed for the intellect which is a more perfect
faculty. However, St. Thomas Aquinas acknowledges the
necessity and hence the reliability of sacred doctrine in
his Summa Theologica. `Whether, besides the philosophical
disciplines, any further doctrine is required?' he asks,
and his reply is in the affirmative: `It was necessary for
man's salvation that there should be a doctrine revealed by
God, besides the philosophical disciplines investigated by
human reason ... because man is directed to God as to an
end that surpasses the grasp of his reason'.3 Consequently,
it becomes to a certain extent difficult to locate the
similarities and differences between Aquinas and Scotus.
They both seem to be inclined alike for the necessity and
therefore the reliability of faith as knowledge. 

The prologue of the Ordinatio determines two positions: in
the beginning that of St. Thomas and later the position of
St. Augustine. But with neither of them does Scotus agree
totally. Although he must have had St. Thomas in mind at
least with respect to some philosophers and theologians, he
must be credited with fairness to Aquinas. It is with an
allusion to the works of St. Thomas that Scotus' triple
argument in defense of the necessity and therefore
reliability of faith sets out: distinct knowledge of his
end through cognition is necessary for every agent. (n. 13)
Furthermore, in his replies to the arguments of the
philosophers Scotus makes an explicit reference to St.
Thomas by citing him by name; moreover, he quotes from the
aforementioned very first article of the Summa. (n. 79)
With three principal considerations Scotus sets forth the
view that divine revelation is necessary and that
scientific knowledge derived just through sense-experience
and reason is not sufficient. A human being is a rational
agent and as such requires a Adistinct knowledge of his
end. (nn. 13-15) Even if reason suffices to prove that
beholding God is the end of man, it could not conclude that
such a vision and enjoyment perpetually becomes and agrees
with a human being perfect both in body and in soul. 

Scotus is of the opinion that the perpetuity of a good of
this kind is the very condition that makes this end
desirable. (n. 16) On a declaration of the immortality of
the human soul - `The intellective soul is incorruptible' -
Scotus reasons that it can not be proved: It can be stated
that although there are probable reasons for this second
proposition, these are not demonstrative, nor for that
matter are they ever necessary reasons.4 Starting from a
framework in which natural agents desire the end on account
of which they operate, the first persuasive argument
considers this to be necessary also for a knowing agent.
Scotus points out that human beings can not know their end
distinctly from natural sources. He utilizes passages of
Nicomachean Ethics to demonstrate that even the Philosopher
himself was not very clear on this topic. (n. 14) We can
show something from the behavior manifest to us of a
substance and that something would just be - that such an
end may agree with such a nature. The proper end of no
substance is cognized by us. We do not experience or
cognize any acts to belong to us in this life so that
through them we may naturally know some special end to
agree with our nature. (n. 15) 

Scotus' second persuasive argument is as follows: `It is
necessary for every conscious agent in pursuit of an end to
know by what means and in what way such an end may be
attained; and also the knowledge of all things which are
necessary to that end is necessary; and thirdly the
knowledge that all that suffices for such an end is
necessary'. (n. 17) And in his third and last persuasive
argument Scotus enjoins that if the enjoyment of God is in
itself manÙs end, God acts contingently and we can not
ascertain with the certainty of necessity that God does or
does not accept merits as worthy of such a reward. (n. 18)
(III) Conclusion 

One student of Scotus has explained the situation with
respect to Scotus and Aquinas in the following way: we do
not know our nature in that aspect which would enable us to
deduce its spiritual destiny from the nature. Though by the
light of nature we may know that man is a spiritual being
or even accept St. Thomas' proof that he needs grace, yet
we can not infer from man's nature the promises of the
Gospel (Duns might say rather, `the contingent will of
God'), and therefore, since the Gospel is the mending or
fulfilment of Creation, we can not from our knowledge of
man's nature infer that final end which depends upon the

It is evident from the prologue that the conclusion above
about St. Thomas and Duns Scotus follows from their
respective thoughts on faith. Scotus quotes from St.
Augustine to back up the criticism of his own standpoint
that although man can naturally know of his natural end,
indeed he can not know about his supernatural end: `the
possibility of having faith like the possibility of having
charity belongs to human nature, but the actual possession
of faith like the actual possession of charity pertains to
the grace vouchsafed to the faithful'.6 Scotus concedes to
St. Augustine that God is the natural end of human beings.
The part he will not allow is that God naturally may be
attained: the possibility of having charity as it is a
disposition with respect to God in Himself under the proper
notion of loving agrees with human nature according to a
special notion, which is not common to it and to sensibles;
and hence, that potentiality of human beings is not
naturally recognizable in this life, just as man is not
known under the notion by which his potentiality is his
own. (n. 32) 

Scotus' explicit quotation from the Summa of Aquinas
clarifies the difference between their teachings. Aquinas
says that `there is no reason why those things which are
treated by the philosophical disciplines, so far as they
can be known by the light of natural reason, may not also
be treated by another science so far as they are known by
the light of the divine revelation'.7 He thus in this
manner implies that sacred doctrine by way of the divine
revelation is not absolutely necessary. In fact St. Thomas
Aquinas says in the same article of the Summa the
following: `in order that the salvation of men might be
brought about more fitly and more surely, it was necessary
that they be taught divine truths by divine revelation'.8
It is a question of more or less fitness and certainty and
hence the logical consequence is that sacred doctrine may
not be as good and reliable as reason based on
sense-experience; the reliability of faith as a
justification of true belief may be doubted. 
1 John Hospers, An Introduction to Philosophical Analysis ,
2nd ed. (1967; rpt. London: Routledge and Kegan Paul Ltd.,
1970) p. 140. 

2 John Duns Scotus, Ordinatio Prologus, Opera Omnia I
(Civitas Vaticana: Typis Polyglottis Vaticanis, 1950). 

3 Summa Theologica , p. I ch. 1 q. 1.
4 Allan Wolter, O.F.M., trans., Philosophical Writings: A
Selection, The Nelson Philosophical Texts, ed. Raymond
Klibansky, The Library of Liberal Arts (1962; rpt.
Indianapolis: Bobbs-Merrill Educational Publishing, 1978)
pp. 146-147. 

5 Nathaniel Micklem, Reason and Revelation: a question from
Duns Scotus (Edinburgh: Thomas Nelson and Sons Ltd., 1953)
p. 18. 

6 Ibid. , p. 17; n. 22.
7 Anton C. Pegis, ed., Basic Writings of Saint Thomas
Aquinas (2 vols., New York: Random House, 1945) p. 6; p. I
ch. 1 q. 1. 

8 Ibid. 

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