Bonhoeffer's epistemology

The contrast between dogma vs science/sociology to which
Mike Perry referred in a recent letter is explicitly 
acknowledged by Bonhoeffer in the fifth chapter of
Sanctorum Communio: (Upper case text reflects the italics
of the original.)

Der Begriff der Kirche ist nur denkbar in der Sphaere der
gottgesetzten Realitaet, d.h. er ist nicht deduzierbar.
Die REALITAET DER KIRCHE IST EINE OFFENBARUNGSREALITAET,
ZU DEREN WESEN es gehoert, entweder geglaubt oder geleugnet
zu werden. Will man also ein adequates Kriterium fuer die
Berechtigung des Anspruchs der Kirche, Gemeinde Gottes zu sein,
finden, so ist das nur moeglich, wenn man sich in sie hineinstellt,
glaubend sich ihrem Anspruch beugt. Nun ist freilich Glaube
keine moegliche Methode, zu wissenschaftlicher Erkenntnis
zu gelangen, sondern er ist, als auf den Offenbarungsanspruch
hoerender, gegebene Voraussetzung fuer positive theologische
Erkenntnis.         Sanctorum Communio  S. 80-81

I translate as follows:

"The concept of (the) church is conceivable only in the sphere
of divinely determined reality. i.e., the concept of (the)
church is not deducible. The REALITY OF (THE) CHURCH IS A
REALITY OF REVELATION, WHOSE ESSENCE entails either to be
believed or to be denied. If therefore one wishes to find
an adequate criterion to justify the claim of the church
that it is the community of God, one can do so only by
placing oneself within the church, a believer who submits
to its claim. Admittedly faith is not a possible method
for arriving at scientific knowledge, but faith, (as) being
obedient to the claims of revelation, is the (given)
prerequisite for positive theological knowledge."
Sanctorum Communio, pp. 80-81

If I understand it correctly, the foregoing passage is significant
for at least the following considerations:

a) Bonhoeffer acknowledges that the church, sanctorum communio,
is not susceptible to empirical verification. Its reality is one
of revelation and requires to be accepted by faith, a circumstance
which no one familiar with the secular history of the church
or its secular activities will deny. The _real_ church, therefore
must be invisible and intangible, existing by virtue of the faith
of its members.

b) Bonhoeffer implies the existence of "positive theological
knowledge." Bonhoeffer here does to Comte what Marx did to Hegel,
standing the proponent of "positive knowledge" so to speak on his
head. I myself have always felt disadvantaged, inasmuch as I have
never had "positive knowledge" of anything.  Hence I have always
been puzzled by Comte's assertion of its existence. My puzzlement
is compounded by the implication of Bonhoeffer's text that I might
have missed out on positive theological knowledge as well.

c) I am embarrassed by Bonhoeffer's admission that faith is not a
possible method of arriving at scientific knowledge, since I myself
had come to the opposite conclusion, inasmuch as all "scientific
knowledge" that I have ever encountered has been based on faith,
as defined by St. Paul in his Epistle to the Hebrews: "Now faith is ...
the evidence of things not seen."  I am prepared, if some listmembers
are made uncomfortable by a single faith that permeates _all_ human
experience, to distinguish between a secular faith and a sacred faith,
and leave issues concerning sacred faith to the theologians to untangle.
In any event the (secular) faith that informs modern science seems to
me to be universally denied because it is so pervasive as not to be
recognized for what it is.
                                             Ernst Meyer