ect; secondly, on the part of the medium;
thirdly, on the part of the subject. The difference of perfect and
imperfect knowledge on the part of the knowable object is seen in the
"morning" and "evening" knowledge of the angels: for the "morning"
knowledge is about things according to the being which they have in
the Word, while the "evening" knowledge is about things according as
they have being in their own natures, which being is imperfect in
comparison with the First Being. On the part of the medium, perfect
and imperfect knowledge are exemplified in the knowledge of a
conclusion through a demonstrative medium, and through a probable
medium. On the part of the subject the difference of perfect and
imperfect knowledge applies to opinion, faith, and science. For it is
essential to opinion that we assent to one of two opposite assertions
with fear of the other, so that our adhesion is not firm: to science
it is essential to have firm adhesion with intellectual vision, for
science possesses certitude which results from the understanding of
principles: while faith holds a middle place, for it surpasses
opinion in so far as its adhesion is firm, but falls short of science
in so far as it lacks vision.

Now it is evident that a thing cannot be perfect and imperfect in the
same respect; yet the things which differ as perfect and imperfect
can be together in the same respect in one and the same other thing.
Accordingly, knowledge which is perfect on the part of the object is
quite incompatible with imperfect knowledge about the same object;
but they are compatible with one another in respect of the same
medium or the same subject: for nothing hinders a man from having at
one and the same time, through one and the same medium, perfect and
imperfect knowledge about two things, one perfect, the other
imperfect, e.g. about health and sickness, good and evil. In like
manner knowledge that is perfect on the part of the medium is
incompatible with imperfect knowledge through one and the same
medium: but nothing hinders them being about the same subject or in
the same subject: for one man can know the same conclusions through a
probable and through a demonstrative medium. Again, knowledge that is
perfect on the part of the subject is incompatible with imperfect
knowledge in the same subject. Now faith, of its very nature,
contains an imperfection on the part of the subject, viz. that the
believer sees not what he believes: whereas b