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APPENDIX I
Lucretius’s Arguments Against Immortality
in De rerum natura 3.425-829.
Overview:
A. Arguments against the survival of the soul after death (3.425-669). Proofs 1-15.
1. Proof from atomic structure of the soul
2-3. Proofs from parallelism of mind and body
4-8. Proofs from the sympatheia of mind and body
9-15. Proofs from the structural connection of mind and body
B. Arguments against the pre-existence of the soul (3.670-783). Proofs 16-25.
C. General arguments against immortality (3.784-829). Proofs 26-29.
A. Against survival of the soul after death:
1. (3.425-44). Proof from the atomic structure of the soul (as set out in DNR 1-2):
Given that the soul is a fine-material substance, like an invisible gas, when the vessel
(vas; stegazon in Greek) containing the gas-type substance is shattered like a balloon
(in death), the contents dissipate.
2. (3.445-58) Argument from the parallelism in the experiences of mind and body:
Both move from weakness in youth to growth and strength, then to weakness again in
old age.
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3. (3.459-62) Another parallelism: As the body is affected by pain, so is the mind by
grief: quare participem leti quoque convenit esse.
4. (3.463-75) Argument from the sympatheia between mind and body: Mind is often
affected by disease of the body. The body experiences pain and disease as causes of
death; these are physical phenomena, hence the soul, which is also aware of pain and
disease, must be physical.
5. (3.475-86). Another sympatheia: The reason that wine affects all parts of the body
(not just digestion) is that its effects are carried everywhere by the soul, which is also
affected by the wine; therefore the soul is material and mortal. If the cause was
stronger, i.e., strong enough to cause death to the body, then it would kill the soul too,
whose sympatheia is shown by its being affected by wine also.
6. (3.487-509). Example of epilepsy: This disease affects the soul as well as the body,
while recovery from an epilectic fit restores both body and soul.
7. (3.510-525). Argument from medicine: The mind can be cured by medicine, like
the body, which shows that it is mortal. In principle, since all change implies the
possibility of death, medicinal cures imply liability to death, since medicine can
change the soul. But ‘what is immortal does not permit its parts to be altered or any
matter to be added or to slip away.’ (At neque transferri sibi partis nec tribui vult /
immortale quod est quicquam neque defluere hilum.)
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8. (3.526-47). Argument from the gradual departure of the soul. Sensation and life
leave the body gradually, not instantaneously (recalling the famous case of Socrates’
death in the Phaedo). The implied conclusion is as follows: If the soul can depart
gradually, it must have parts; therefore it is not immortal, since only what is
immaterial can be immortal.
9. (3.548-58). Argument from interdependence of soul and body: The mind, like the
sense organs, is a part of the body, and cannot exist alone without it. Thought is the
same as sensation. (The inference can be drawn that, as both exist in time, both must
be physical processes.)
10. (3.558-79). Another argument from interdependence: Soul cannot exist without a
body to enclose it; soul and body owe their life to their intimate connection. The soul
cannot perform its functions, like sensation, without the body, nor the body its
without the soul. Leaving the body, soul’s particles dissipate in air.
11 and 12. (3.580-614). Two related proofs. When the soul is separated from it, the
body wastes away. If the soul is driven outside the body, it dissipates into the air and
cannot perform its vital functions, robbed of its shelter, tegmine dempto.
13. (3.615-23). Argument from the localization of mind: The mind has its fixed place
in the body. Mind could not exist except in the heart of a living person: this is a
‘form-follows-function’ argument. It couldn’t do what it does located somewhere else
in the body. [The soul is localized; therefore material; therefore mortal.]
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14. (3.624-33). An immortal soul would have to preserve its corporeal sense-organs in
order to do the things it is imagined doing in the afterlife by old writers like Homer. A
reductio ad absurdum, which depends on Lucretius’s Epicurean assumption that the
life of something is nothing more than its sensations. Thought is a sensation, and
sensation requires body; therefore the mind dies with the body.
15. (3.634-69). The soul can be divided together with the limbs of the body and is
therefore not immortal. Lucretius gives the example of bodies that suddenly lose
limbs in battle. Severed limbs and heads still briefly move and have sensation. This
shows that the soul-atoms were divided among the parts of the body. [Therefore soul
is divisible, therefore changeable; therefore mortal; an assumption is that one body
cannot have many souls.]
B. Against pre-existence (arguments directed against Pythagoreans and Platonists):
16. (3.670-80). The soul has no memory of a former existence.
17-18. (3.679-712). Two related proofs from the close connection of soul and body:
Lucretius here argues against what later becomes the Christian position (that a
complete and fully-formed immortal soul is grafted into the body at the time of birth).
What would be the physical results of the entry of an immortal soul (i.e. an alien
substance) into the body at birth? Absent from the prenatal development of the child,
it could not have the close connection with the body needed to support sensation
throughout the body, so it couldn’t animate the body. This is a proof directed against
the argument of Pythagoreans and Platonists that the soul is only adventitiously
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connected to the body, like a man in prison, or like a pilot in a ship; but the argument
is usable against the pre-Thomistic Christian psychology as well. Proof 18: a soul
that is complete and fully formed at the moment of entry into the body would
immediately have to change form: it would disperse through the body and a new soul
would be created (as food becomes something else in our body). Hence, pari ratione
the soul cannot leave the body at death without changing form and therefore
(minimally) identity.
19. Empirical argument: There is soul in the body as well as in the worms which
spring from the rotting corpse after death. Where do worms in the rotting body come
from? From rearrangement of the soul-atoms after death, showing that the soul,
before birth as well as after death, lacks unity and cohesiveness in se.
20-24. Five closely related proofs, also directed against Pythagoreans and
metempsychosis (3.741-75). These all point to the common growth of the soul with
the body; the soul is said to develop from seeds (semina). All these proofs rely on the
Epicurean idea that a soul has determinate atomic structure (in some ways like a
gene), as it is composed of nuclei of wind, air, heat and ‘fourth nature’. This accounts
for hereditary characteristics. The Pythagorean account cannot account for hereditary
characteristics; if it were true, animals of the same descent would differ randomly.
25. (3.775-83). Argument ad absurdum. The absurdity of souls fighting over
possession of a body, waiting for the conception of a body, then striving for priority
of entry.
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C. General considerations against immortality:
26. (3.784-799). Everything has its fixed place in nature, and within the protecting
vessel of the human body is where the soul belongs. A tree can’t exist in the sky or
fish in the fields, nor blood in wood.
27. (3.800-5). It is absurd to suppose that an immortal soul could share the feelings
and experiences of a mortal body. (This is probably directed against Plato’s famous
description of just this in Timaeus 43a-44a). Behind this is the whole Platonic
conundrum of how the eternal/ immaterial/universal/immutable/simple can inhabit
what is temporal/material/ particular/ mutable/partible. Since the soul is subject to
material potencies is has to be material, therefore mortal.
28. (3.806-18). Argument from the nature of the eternal (as conceived by
materialists): things can only be eternal if (a) they are adamantine enough to repel all
blows and so cannot be penetrated; (b) if, like the void, they cannot be touched or
affected in any way; or (c) if they lack space outside of themselves into which they
can be dissolved, like the universe. But the soul is not like any of these, [therefore it is
mortal].
29. (3.819-29). The Platonic conception that the human soul is protected from
dissolution by an intrinsic vitality (like the bodies of the gods) does not survive
empirical scrutiny – e.g. the fact that the human soul shares the body’s evils, as
argued above, proofs 4-7. In short, summarizing 28 and 29, the human soul does not
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share the conditions of immortality satisfied by atoms, the void, the universe and the
gods.
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APPENDIX II
Ficino’s critique of Lucretius
in the Platonic Theology: Some examples
Against major Lucretian doctrines other than the mortality of the soul
1. DRN 2.646-8. Against the idea that the gods have no concern for us and ‘lower
things’ generally, Ficino observes, following Aquinas, that God doesn’t see the things
in themselves but through his own essence; i.e. he doesn’t ‘lower himself’ to perceive
individuals qua individuals. See PT 2.9.7.
2. DNR 2.1058-64. See PT 2.13.6-9. Ficino critiques the Lucretian idea of ‘emergent
order’ [order emerging from random events such as the clinamen], ‘as if someone
were to suppose that wisdom was born from stupidity, or light from darkness’. His
answer is to invoke the argument from design. In so doing he argues for the
interdependency of living beings: ‘Think of plants and animals: their separate parts
are so designed that the position of one is to the advantage of another; they serve each
other.’ He also comes close to what would today be called, in anti-Darwinian theory,
the argument from ‘irreducible complexity’: ‘in the end all the world’s parts come
together to form for the whole world a unique harmonious beauty from which nothing
can be subtracted and to which nothing can be added.’ (This canon of beauty is drawn
from the classical test of perfect discourse in rhetoric.) Ficino explains the ability of
nature to repeat features of its design over time by appeal to the idea of seeds
(semina) which are teleological in character. Order can’t come from disorder. He also
answers Lucretius’ charge that nature has imperfections with a Stoic argument of his
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own, that apparent imperfections in nature subserve a larger perfection, that of the
whole, which could not exist without the imperfection of parts. These preliminary
arguments are ultimately used to answer Lucretius’s proofs 20-24.
Against Lucretius’ arguments for the mortality of the soul
3. Response to Proof 2. TP 8.2.4-5. On the contrary, says Ficino, the relationship of
soul to body is that of art to the instruments it uses (Aristotle, De anima 3.5); it’s the
instruments that wear out, not the art. Sometimes the soul grows stronger as the body
grows weaker. This passage also contains a response to Proof 9: Mental processes of
growth (like acquiring a piece of knowledge or a virtue) can happen instantaneously;
so they don’t resemble bodily processes. When a young man acquires a virtue, this is
not a matter of increasing a quantity but of acquiring a spiritual harmony, whose
emergence from disharmony can be instantaneous.
4. Response to Proof 4. TP 8.2.6-12. When the body is sick or ailing, the soul is
preoccupied with taking care of it; hence it doesn’t perform its contemplative
functions well; but when the body is at peace, it returns to the search for truth. The
food of the body and of the soul are different in kind. The food of the soul is truth.
The senses follow the changeability of the body but the mind seeks the unchanging
truth; truth is incorporeal. ‘How can soul be mortal, if it feeds on immortal truth?’
Note that much of Books 6-8 are devoted to refuting materialistic conceptions of soul.
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5. Another response to proof 4. TP 9.5.25 (Lucretius is not mentioned). Example:
loss of memory from a head injury. Does this show that thinking is based in the body?
No: Ficino gives an Aristotelian anwer (species are in the mind, but at rest, since they
are not activated by sensation) and a Platonic answer (cognition and memory are
remitted because the soul is intent on care for the body). In the latter Ficino makes use
of the scholastic theory of intension and remission of forms.
6. Another response to proof 2. TP 9.5.26. (In a chapter ‘That the mind operates
without the body’). This responds to DRN 3.607-14 according to the notes to the
Allen-Hankins edition, but on further consideration Ficino is more likely responding
to proof 2. The soul does not weaken with old age, but the spiritus dries up, causing
mind to turn within away from body; then it perceives the future and mysteries (which
is one reason why old age is religious). Contra Lucretius, the soul actually gets
stronger when the body weakens.
7. Response to proof 7. TP 9.5.27: Many people brought back from the brink of
death by doctors recover their minds but not their bodies. Ficino reverses Lucretius’
claim in proof 7 from medicine: Ficino as a Galenist admits that medicine affects the
mind, but he observes that it does so differently from the way it affects the body; its
effect is not parallel. ‘Who would claim that the exit of body and soul from life is the
same when their return is not the same?’
8. Response to Proof 12. The rest of TP 9.5.27 is a direct response to DNR 6.612-14,
even down to Ficino’s reuse of the image of the snake that sloughs its skin. Another
response to Proof 12 is found at TP 16.8.1-2 and following:
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Quare, si caelestes animi sunt, a terris tam inviti discendunt? … Mitto quod
non omnes morientes lugent; lugent autem nascentes omnes, et quasi inviti a
lacrimis terrenum hoc iter auspicantur tamquam exilium. … At ea pars
animae abit invita quae corpori dumtaxat alendo atque tuendo tributa est,
quoniam abeundo naturali quodam officio vacat et amicum deserit suum.
If souls are heavenly beings why do they depart so unwillingly from earth? …
I set aside the fact that not all who are dying lament, but that all who are being
born do lament, and that they enter upon this earthly journey as an exile,
unwillingly it would seem from their tears. … But that part of the soul
assigned to the body merely for nourishing and protecting does depart
unwillingly, since in leaving it no longer performs an office natural to it: it is
deserting its friend.
9. Response to Proof 14. TP 16.8.8. Ficino counters this proof of the Lucretiani with
an argument from self-consciousness – Ubi iam nunc, quamvis cum corpore ducat
vitam, agit tamen sine ipso nonnihil, quando iudicat quid sit et quale idipsum quod
dicitur sine corpore operari. (‘Even now, though it leads a life with the body, it does
something nonetheless without the body when it forms a judgment about what it is
that is said to act without the body and about what kind it is.’) The reflexive character
of intellect shows its essence is not the same as the essence of sensus.