The book is Proclus' Elements of
. By 1017 this fifth-century text had likely made
its way to Dar al-Hikma. It would have been nestled in the
cabinet beside its more popular (and pseudonymous) abridgment,
Aristotle's Book of Causes
The Elements of
Theology is Proclus' systematic exposition of
Neoplatonism. Its primary deduction — the immortality of the
soul. The Elements may be the most orderly proof of
immortality ever composed by a Hellenic philosopher. For
readers who've not seen the text, it will be instructive at this
time to study a few Elements which abstract Proclus' argument.
This presentation will pass quickly to a critique. The
critique brings Proclus' image of the soul into focus, as it
disentangles the knot of his immortality argument.
This exercise in
criticism is preparation for the modern metaphysical thesis which is
to come — and it's an exercise which this author dislikes. I
must raise critical remarks across three ascending chapters before
pausing to bolt the remarks together, as a single thought, in
the preparatory conclusion of Chapter 7. Many readers may
imagine the critical material to be unnecessary, or even
pointless. It is neither; but here I think a longwinded
explanation would take us too far afield, so I'll refrain.
Chapter 7 will come soon enough. Only, here especially I must
beg for the reader's patience and trust.
We take up the seamed volume. Leather opens to
paper, paper opens to words.
The text of Proclus'
consists of two hundred and eleven Neoplatonic
propositions, organized by a method similar to that which
mathematicians use in the construction of mathematical proofs.
When a mathematician wants to prove a novel
theorem, he uses in his proof theorems which have been proved
before. Those axioms are foundational, in the sense that they
are uncontroversial and accepted as authoritative by the
In the same spirit
Proclus starts at first principles, intuitively. He proceeds
to build increasingly abstract propositions on top of this
foundation, citing his foundational propositions as the authorities
for subsequent arguments. Proclus may have chosen his method
with a mathematical structure in mind.
Be that as it may, the work is ordered
He composes each proposition of two
parts: an argument and a conclusion. (In mathematical
terms, the argument is analogous to a proof, and the conclusion to a
theorem proved axiomatically.)
The conclusion comes
first. Proclus states it in a single sentence.
After the conclusion
comes the argument, in which Proclus deduces the conclusion he has
just stated. Each argument is one paragraph in
A few choice
propositions will make clear Proclus' method. Ten of the 211
propositions are reprinted below.
These particular propositions constitute a
significant portion of Proclus' argument for the soul's
indestructible and imperishable nature. The propositions are
cogent, although numbered in a way which puts the selected ten
slightly out of order when read in isolation. For this reason
I have moved two propositions forward. So ordered the selected
ten state much of Proclus' case.
Here are the ten
propositions, reprinted in full, with summary notes affixed.
Afterwards, a twenty-first-century
of these noble fifth-century thoughts.
Ten propositions from Proclus' Elements of
Prop. 33. All that proceeds from any principle and
reverts upon it has a cyclic activity.
For if it reverts upon that principle whence it proceeds (Prop.
31), it links its end to its beginning, and the
movement is one and continuous, originating from the unmoved and
to the unmoved again returning. Thus all things proceed in a
circuit, from their causes to their causes again. There are
greater circuits and lesser, in that some revert upon their
immediate priors, others upon the superior causes, even to the
beginning of all things. For out of the beginning all things
are, and towards it all revert.
Proposition 33 introduces "cyclic activity,"
conceived as the necessary return of any created thing to the source
of its creation. The water cycle may serve as an illustration
of the concept:
The sun frees water from
the ocean as vapor. That vapor "proceeds" away from the ocean;
forming clouds, raining upon the land, and trickling into
rivers. The rivers "revert" the water to its origin, the
ocean. Proclus envisions all existence as running through such
Prop. 17. Everything originally self-moving is
capable of reversion upon itself.
For if it moves itself, its motive activity is
directed upon itself, and mover and moved exist simultaneously as
one thing. For either it moves with one part of itself and
is moved in another; or the whole moves and is moved; or the whole
originates motion which occurs in a part, or vice
. But if the mover be one part and the moved
another, in itself the whole will not be self-moved, since it will
be composed of parts which are not self-moved: it will have
the appearance of a self-mover, but will not be such in
essence. And if the whole originates a motion which occurs
in a part, or vice versa
, there will be a part common to
both which is simultaneously and in the same respect mover and
moved, and it is this part which is originally self-moved.
And if one and the same thing moves and is moved, it will (as a
self-mover) have its activity of motion directed upon
itself. But to direct activity upon anything is to turn
towards that thing. Everything, therefore, which is
originally self-moving is capable of reversion upon itself.
Proposition 17 examines cyclic activity in a
self-motive body. Such a body is both its originating cause
and also its effect; both a beginning and an end. By
Proposition 33 the cause to which it reverts must therefore be
Prop. 15. All that is capable of reverting upon
itself is incorporeal.
For it is not in the nature of any body to revert
upon itself. That which reverts upon anything is conjoined
with that upon which it reverts: hence it is evident that
every part of a body reverted upon itself must be conjoined with
every other part — since self-reversion is precisely the case in
which the reverted subject and that upon which it has reverted
become identical. But this is impossible for a body, and
universally for any divisible substance: for the whole of a
divisible substance cannot be conjoined with the whole of itself,
because of the separation of its parts, which occupy different
positions in space. It is not in the nature, then, of any
body to revert upon itself so that the whole is reverted upon the
whole. Thus if there is anything which is capable of
reverting upon itself, it is incorporeal and without parts.
Proposition 15 explores the meaning of
"conjunction": the joining of parts adjacent to one
another. Conjunction is only possible where parts are
immediately adjacent. Parts more distant are not
conjoined. As corporeal bodies are composed of parts located
at various distances from one another, those parts cannot wholly
conjoin. Unfortunately, self-reversion requires just such a
union. It follows that self-reverting entities must be without
parts; hence, incorporeal.
Prop. 16. All that is capable of reverting upon
itself has an existence separable from all body.
For if there were any body whatsoever from which
it was inseparable, it could have no activity separable from the
body, since it is impossible that if the existence be inseparable
from bodies the activity, which proceeds from the existence,
should be separable: if so, the activity would be superior
to the existence, in that the latter needed a body while the
former was self-sufficient, being dependent not on bodies but on
itself. Anything, therefore, which is inseparable in its
existence is to the same or an ever greater degree inseparable in
its activity. But if so, it cannot revert upon itself:
for that which reverts upon itself, being other than body (Prop.
15), has an activity independent of the body and not conducted
through it or with its co-operation, since neither the activity
itself nor the end to which it is directed requires the
body. Accordingly, that which reverts upon itself must be
entirely separable from bodies.
Proposition 16 strengthens Proposition 15. It
argues that any taint of corporeality on a self-reversive entity
would render self-reversion impossible. For this reason
self-reversion must be not only incorporeal, but also cleanly
separable from all corporeal bodies.
Prop. 43. All that is capable of reversion upon
itself is self-constituted.
For if it is by nature reverted upon itself, and
is made complete by such reversion, it must derive its existence
from itself, since the goal of natural reversion for any term is
the source from which its existence proceeds (Prop. 34).
If, then, it is the source of its own
well-being, it will certainly be also the source of its own being
and responsible for its own existence as a substance. Thus
what is able to revert upon itself is self-constituted.
Proposition 43 equates "well-being" with completion
of the reversive cycle. If an incorporeal body can act as the
source of its own well-being by reverting upon itself, it is
considered to be self-constituted.
Prop. 46. All that is self-constituted is
For if it be destined to perish, it will then
desert itself and be severed from itself. But this is
impossible. For being one, it is at once cause and
effect. Now whatever perishes is in perishing severed from
its cause: for each thing is held together and conserved so
long as it is linked with a principle which contains and conserves
it. But the self-constituted, being its own cause, never
deserts its cause since it never deserts itself. Therefore
all that is self-constituted is imperishable.
Proposition 46 draws upon Proposition 43 in arguing
for the imperishable nature of the self-constituted. The
self-constituted is imperishable because it is never severed from
its principle cause (which is itself).
Prop. 49. All that is self-constituted is
For anything which is not perpetual must be so in
one of two ways, either as being composite or as existing in
But the self-constituted is simple, not
composite (Prop. 47),
and exists in itself, not in another
It is therefore perpetual.
Proposition 49 argues that the self-constituted
exists perpetually because it has no composite parts susceptible to
decomposition; and also because it exists without external
Prop. 83. All that is capable of self-knowledge
is capable of every form of self-reversion.
For that it is self-reversive in its activity is
evident, since it knows itself: knower and known are here
one, and its cognition has itself as object; as the act of a
knower this cognition is an activity, and it is self-reversive
since in it the subject knows itself. But if in activity,
then also in existence, as has been shown: for everything
whose activity reverts upon itself has also an existence which is
self-concentrated and self-contained (Prop. 44).
Proposition 83 addresses cognition for the first
time. Cognition is shown to be a kind of self-reversive
activity, as demonstrated in the act of self-knowledge. Hence
self-knowledge must share in those traits common to any
self-reversive activity. For example, it must have an
existence which is self-contained. (By inference, its
existence must also be self-constituted, per Prop. 43.)
Prop. 186. Every soul is an incorporeal
substance and separable from body.
For if it know itself, and if whatever knows
itself reverts upon itself (Prop.83), and what reverts upon itself
is neither body (since no body is capable of this activity
[Prop.15]) nor inseparable from body (since, again, what is
inseparable from body is incapable of reversion upon itself, which
would involve separation [Prop.16]), it will follow that soul is
neither a corporeal substance nor inseparable from body. But
that it knows itself is apparent: for if it has knowledge of
principles superior to itself, it is capable a
of knowing itself, deriving self-knowledge from
its knowledge of the causes prior to it.
Proposition 186, like Proposition 83, applies
previous results to the special activity of cognition. The
results apply equally to cognition's home, the soul. The soul,
being self-knowing, must also be incorporeal and separable from the
Prop. 187. Every soul is indestructible and
For all that is capable of being in any way
dissolved or destroyed either is corporeal and composite or has
its being in a substrate: the former kind, being made up of
a plurality of elements, perishes by dissolution, while the
latter, being capable of existence only in something other than
itself, vanishes into non-existence when severed from its
substrate (Prop. 48).
But the soul is both incorporeal and
independent of any substrate, existing in itself and reverting
upon itself (Prop. 186). It is therefore indestructible and
Proposition 187 culminates Proclus' case for the
soul's indestructible and imperishable nature. Proclus will
proceed to interpret this result as support for a theory in which
the soul undergoes an unceasing cycle of reincarnations.
Ten propositions from Proclus'
have now been arranged for display, propped on
velvet steps as it were. It's time to subject these
propositions to a test of truth — an unfettered critique of Proclus'
Chapter 4: Reversion in the Corporeal
Chapter 3 Endnotes
The Iraqi encyclopedist al-Nadim listed Proclus'
Elements of Theology
in his bibliographical dictionary
, A.D. 987. See Majid Fakhry, A
History of Islamic Philosophy
(New York: Columbia University
Press, 1970) 40. Apparently Proclus' original text had been
translated and was in circulation among Arab scholars by that
time. (This inference is not certain: no complete Arabic
translation from that era has yet been found.)
Proclus was himself a capable mathematician.
See, for example, his commentary on Euclid's Elements
, as in:
Proclus, Proclus: A Commentary on the First Book of Euclid's
, trans. Glenn R. Morrow (Princeton: Princeton
University Press, 1970).
Proclus may have written the Elements of
as a continuation of his Elements of Physics
. See E. R. Dodds, trans., intro., and commentary, The
Elements of Theology
, by Proclus, 2nd
Clarendon Press, 1963) xvii-xviii. Proclus' style follows that
of mathematical synthesis (deduction), and also Platonic
hypothesis. See Dodds 1963, xi, note 4.
For examples of logical weaknesses, see Dodds 1963,
All quotations from Dodds 1963.
Dodds 35, Prop. 31. " All that proceeds
from any principle reverts in respect of its being upon that from
which it proceeds."
This implies another syllogism, whose conclusion
Proclus does not draw. Premising Props. 17 and 15, we can
conclude that self-moving bodies must also be incorporeal.
Proclus does not, however, compose the syllogism.
Dodds 37, Prop. 34. " Everything whose
nature it is to revert reverts upon that from which it derived the
procession of its own substance."
Dodds 49, Prop. 48. " All that is not
perpetual either is composite or has its subsistence in
Dodds 47, Prop. 47. " All that is
self-constituted is without parts and simple."
Dodds 43, Prop. 41. " All that has its
existence in another is produced entirely from another; but all that
exists in itself is self-constituted."
Dodds 77-79, Prop. 44 . "All that is
capable in its activity of reversion upon itself is also reverted
upon itself in respect of its existence."
Dodds 49, Prop. 48. " All that is not
perpetual either is composite or has its subsistence in
Dodds 181, Prop. 206. "Every particular
soul can descend into temporal process and ascend from process to
Being an infinite number of times."