From: altar@beaufort.sfu.ca (Ted Wayn Altar)
Subject: Plant Pain 1
Organization: Simon Fraser University, Burnaby, B.C., Canada
Date: Fri, 18 Dec 1992 16:54:17 GMT

I see that the old chestnut of "plant pain" has again been
invoked.  Apparently, this is a common argument and so, dear
reader, permit me to re-post an older message of mine that
attempts to address this issue in a discursive, but also
humourous manner.

				Happy Holiday Season,

				          ted




           THE DIVERSIONARY TACTIC OF PLANT PAIN

                         TED ALTAR



A.  HOW MIGHT CHARLES DARWIN RESPOND?

 With respect to this extravagant debate on plant pain we
have at hand a most promiscuous adjoining of some verified
facts with improper inferences.  This reminds me of a story
(probably apocryphal as are so many of the best anecdotes)
about Charles Darwin who in his later years was the guest of
a family whose two boys approached him with a clever
deception.  Using some old desiccated specimens of insects,
they had deftly attached the wings of a butterfly, the head
of a beetle and the legs of a grasshopper to the body of a
centipede.  "We have this strange bug we caught some time
ago" they innocently said, "Can you tell us what it might
be?"  Darwin squinted and examined it as best he could and
asked, "Can you remember if it hummed when you caught it?"
he asked in all seriousness.  Without smirking, the boys
answered yes, whereupon Darwin replied, "Just as I thought,
it is a humbug!"


B.  THE SPECIOUS INFERENCE OF PLANT PAIN.

No doubt we all have been amazed by much "humbug" on this
conference, but maybe no greater example is to be given than
that of "plant pain".  Those whose common sense remains
intact will have no difficulty in accepting as sufficient
the following:

     1.  Our best science to date shows that plants lack any
    semblance of a central nervous system or any other system
    design for such complex capacities as that of a conscious
    suffering from felt pain.

    2.  Plants simply have no evolutionary need to feel pain.
    Animals being mobile would benefit from the ability to sense
    pain; plants would not.  Nature does not create gratuitously
    such complex capacities as that of feeling pain unless there
    should be some benefit for the organism's survival.


Well, as Oliver Goldsmith realistically observed, "Every
absurdity has its champions to defend it".   And yes, we
have some defenders who would ignore common sense and argue
for plant pain.  Remarkable!.  But maybe not so remarkable
if we keep in mind the motivation for such humbug.  The
following argument has repeated been voiced against the
concern of us who would forward greater regard for the
woefully neglected and grievous suffering of those sentient
creatures who cannot defend, nor articulate in words, their
plight.  The following `reductio ad absurdum' is supposed to
suffice as an irrefutable trashing of animal rights.

 Premise(1)   If a sentient being can consciously experience
             pain and suffering, then it is wrong to inflict
             pain & suffering on such a sentient being
 Premise(2)    Plants are sentient beings that can experience
              pain & suffering
 Conclusion:  It is wrong to inflict pain & suffering on plants.

In order to challenge the acceptability of premise(1), the
anti-AR would have us believe that such a premise
ineluctably leads to the absurd conclusion as stated above.
In order to achieve this coup de grace of animal rights, the
anti-AR who would give little or no coin to premise (1),
would instead introduce the claims of premise(2) as somehow
"scientifically established".  In order to debunk animal
rights as foolish, the anti-AR would first have us believe
in the reality of "plant pain".  Hence, they would attempt
to bury AR into a hole but ironically by first bulldozing a
much deeper one for themselves.



E.  "EVERY ABSURDITY HAS ITS CHAMPIONS TO DEFEND IT"

You say that I am merely spinning my wheels on a straw man?
Then permit me to quote from two of the most loquacious and
articulate promoters of plant "pain" on this conference.

Poster A would bait us with the following argument, an
argument that presumably he still holds as having merit by
virtue of his repeated postings of this worn polemic:

 AR:   "You're crude and unfeeling; you'd probably laugh
          at your mother's  death."
 non-AR: "That's silly, my mother is a human.  A deer isn't."
 AR:   "Deer can suffer, and so do cattle...so I don't eat meat."
 non-AR: "You apparently have no problem killing plants, though."
 AR:   "It's not the same.  Plants aren't animals."
 non-AR: "You're killing a living thing for food, nevertheless."
 AR:   "But it can't feel; it's not sentient; it has no nervous
           system."
 non-AR: "Does dissimilarity rule out 'pain'?"
 AR:   "Yes."
 non-AR: "That's completely illogical and unscientific."

Note how Poster A would invoke the authority of logic and
science as "completely" on his side.  Next, consider the
assertions of Poster B:

     As a plant molecular biologist with quite a few
     refereed papers on the subject of cellular
     communication in plants, please allow me to debunk the
     unsubstantiated mythology described above.  Plants have
     no *need* to feel pain?  Ridiculous.
     
      When a plant is attacked by an herbivorous insect,
     might it not be in the best interest of the plant to
     mobilize its chemical defenses in other parts of the
     plant in anticipation of further insect attack?  When a
     leaf is infected by a pathogenic fungus, might the rest
     of the plant wish to bolster its chemical and enzymatic
     defenses against the spread of the pathogen?  News
     flash -- the plant *would* benefit, hence the
     development of a systemic (throughout the plant)
     response to local tissue damage by herbivores and
     pathogens. (Many) references available upon request.
     It might easily be argued that *because* plants can't
     move they need effective chemical defenses and
     effective detection and communication. This is the
     case.  You may doubt the sensory and integrative
     abilities of plants, so I invite you to spend a few
     weeks in my lab and learn the truth.  Plants don't have
     nerves, since they don't share a particularly recent
     common ancestor with animals.  Plants feel tissue
     injury and respond quickly, precisely, and with an
     effective battery of defenses.  They don't feel *like
     us*, but it would be a mistake to say that they *don't
     feel*.
     

Here we have the authority of logic, science and "truth"
being imprecated against the sorry state of AR nescience and
"mythology".  Yet, no single published book, or paper in a
scientific journal, has been cited as indeed making this
claim that "plants feel pain".  Sure, there is interesting
evidence about plants reacting to local tissue damage and
even sending signalling molecules serving to stimulate
certain chemical defenses of nearby plants.  But what has
this got to do with supporting the only morally relevant
claim worth considering, namely that "plants FEEL AND SUFFER
from pain"?  Where are the scientific references for this
putative fact?

  Now, dear reader, please be patient with my indulgence to
develop a reasoned reply to such assertive and authoritative
pronouncements about plant pain.


C.  A REDUCTIO ON A REDUCTIO

Although the plant pain promoters are fond of reductios,
they will not likely appreciate the following extension of
their own.  By their "logic", it would equally be the case
that rain clouds behave purposefully in the sense that they
could be said to functionally remove, by way of raining,
excessive moisture that is causing their overstaturation.
Furthermore, rain clouds bear meaningful information about
their level of oversaturation in the form of weight relative
to volume.  Do not clouds, therefore, "sense" (in some
tortured notion of the word) when atmospheric pressure is
insufficient for their moisture content to remain in a
vaporous state?  The promoters of plant pain would have us
believe, against our good common sense, that by the mere
presence of purposive BEHAVIOURS of avoidance and REACTIONS
to tissue damage in plants we therefore must attribute to
plants mental states like that of some kind of "felt pain".
Well, then by the same logic we must do the same to clouds.
In the hole that these promoters of plant pain would dig for
themselves, not only must we accept the thesis of plant
pain, we would also have to swallow some notion of "cloud
sentience"!


D.  THE BEHAVIOURAL INFERENCE OF MENTAL STATES

Lest we forget the ultimate point of what follows, let us
not forget the central thesis of AR.  Simply stated: to the
extent other animals share with us, at least to some degree,
certain morally relevant attributes, then to that extent we
cannot ignore, for the purposes of consistency or justice,
giving due regard and concern towards those animals.  Two
attributes that are arguably relevant are:

     1. our commonly shared interest in the avoidance of
     pain and suffering.
     
     2. and the quality of other animals also being
     subjects-of-a-life which matters to them as to how such
     a life fares well or ill.

Both these qualities posit other animals having certain
mental states.  Also note that in order to speak of "mental
states" proper, we would denote, as common usage would
dictate, that such states are marked by consciousness.  It
is simply insufficient to mark off mental states by only the
presence of purposefulness or intentionality since many
objects, like thermostats and hand calculators, possess
purposeful-looking behaviours or are in an information-
bearing state.

Let us further observe that the attribution of morally
relevant mental states to even humans was at one time an
issue of contention.  For example, consider the case of that
very prestigious scientific apologist of his society's
ambient prejudices, Silas Mitchell, founder of American
neurology.  He claimed that civilized men suffered pain in a
far more ethically relevant manner:

     "In our process of being civilized we have won . . .
     intensified capacity to suffer.  The savage does not
     feel pain as we do" [1].

Today, we can witness a similar prejudice that animals do
not suffer pain to the same capacity as we do.  For
instance, a cow after surgery will right away start eating
grass, therefore it will be said that the cow cannot be
suffering from post-surgery pain.  Just as with the stoic
"savage", who is to say that a cow is not likewise simply
bearing the pain more "heroically" since, as with the non-
civilized human, food is more of an imperative than moaning
with pain; indeed, what else can they do?

So then, how do we properly attribute the existence of
mental states to other animals, or even to ourselves for
that matter, since in the past we have certainly made
mistakes on this score?  As we have seen, the *criterion of
outward functional behaviour* has been faulty with even
humans.  Yet, our plant pain promoters would employ this
same criterion at a different level, turn things on their
head and argue that because plants react to noxious stimuli,
they therefore feel pain.  Now, if the inference of pain
from overt behaviours has been faulty for attributing pain
where we now know pain most assuredly exists, then it is
probably equally faulty in attributing pain where pain does
not exist.  If reactions or behaviours were sufficient, then
we would have to say that a mere toy doll crying and
wriggling, when triggered to do so by certain stimuli, was
indeed in pain.

Similarly, we cannot infer the presence of felt pain simply
by the presence of a sub-class of behaviours which are
functional for an organism's amelioration or avoidance of
noxious stimuli.  Thermostats obviously react to thermal
changes in the environment and respond in a functionally
appropriate manner to restore an initial "preferred" state
thereby maintaining an equilibrium of the status quo.  We
would be dirt foolish, however, to then attribute to
thermostats that therefore they must "sense" or "feel" some
kind of "pain".  Even warning quotes around our terms don't
protect us from such an catachrestic absurdity.

Clearly, the behavioral criterion of even functional
avoidance/defense reactions, is simply not sufficient nor
even necessary for the proper attribution of pain as a felt
mental state.  This is not to say that it is completely
irrelevant for it can at least index the presence of pain in
those creatures we already know or have good reason to
believe experience and suffer pain.  Behaviour by itself
does not index pain in our toy doll or thermostat, but
behaviour does usefully index the occurrence of pain and
suffering in those animals that we already have reason to
believe have the capacity to suffer.


E.  THE RELEVANCE OF SPECIALIZED STRUCTURE

To state the obvious, science, including the biological
sciences, are generally committed to the working assumption
of scientific materialism or physicalism [2].  Now, unless
the "new" biology has returned to some arcane version of
vitalism or dualism, then we must start with the generally
accepted scientific assumption that matter is the only
existent or real primordial constituent of the universe.

Let it be said at the outset that scientific materialism as
such does not preclude the existence of emergent or
functional qualities like that of mind, consciousness, and
feeling (or even, dare I say it, free will), but all such
qualities are dependant upon the existence of organized
matter.  If there is no hardware, there is nothing for the
software to run on.  If there is no intact, living brain,
there is simply no mind.  Now, just for the record it should
also be said that even contemporary versions of dualism or
mind-stuff theories will also make depended their embodied
mental states in this world on the presence of sufficiently
organized matter.

To briefly state the case, what is referred to as non-
reductive materialism [3] would simply consider cognitive
functions like consciousness and mind as emergent properties
of sufficiently organized matter.  Just as breathing is a
function of a complex system of organs referred to
aggregately as the respiratory system, so too is
consciousness a function of the immensely complex
information-processing capabilities of a central nervous
system.  Now, according to such a neo-functionalist account
of mental states, HOW the matter is organized and in with
WHAT materials is not necessarily delimited to the mammalian
brain.  It is possible in theory, that our Alpha Centaurians
who evolved from carrots could equally instantiate some
"higher" functions of consciousness.  This may even be
possible with a future computer given a sufficiently complex
and orderly organization of its hardware and clever
software.  While such a computer does not yet exist, and we
don't yet know about those Alpha Centaurians, we DO know
that certain living organisms on this planet do possess the
requisite complexity of specialized and highly organized
structure for the emergence of mental states.

  In theory, plants could possess a mental state like pain,
but IF, AND ONLY IF there is a requisite complexity of
organized plant tissue which could serve to INSTANTIATE the
kinds of complex information processing that is prerequisite
to such higher order mental states as that of consciousness
and felt pain.  A mammalian brain is not necessary but an
immensely complex hierarchically organized central processor
of some form would be.

  Now, where is the morphological evidence that such a
complexity of tissue in plants exist?  Single cells or even
aggregates of surrounding tissue is not sufficient for there
to be a functional state of felt pain any more than even
todays complex integrated circuit chips evince consciousness
of any kind.  A lot is required and plants just don't have
it.  This is not to say that they cannot exhibit complex
reactions, but we are simply OVER-INTERPRETING such
reactions when they are designated as "felt pain".

With respect to all mammals, birds, and reptiles, we know
that they possess a sufficiently complex neural structure to
enable felt pain plus an evolutionary need for such
consciously felt states.  They possess complex and
specialized organizations of tissue call sense organs, they
possess a specialized and complex structure for processing
information and for centrally orchestrating appropriate
behaviours in accordance with mental representations,
integrations and reorganizations of that information.  The
proper attribution of felt pain in these animals is well
justified, but it is not for plants by any stretch of the
imagination.


                                         ted


I.  REFERENCES

[1] Cited from M. Pernick's (1985) "A CALCULUS OF SUFFERING:
     PAIN, PROFESSIONALISM AND ANESTHESIA IN 19TH C.
     AMERICA.  New York: Columbia University Press.  Cited
     in turn in Bernard Rollin's (1989), "THE UNHEEDED CRY:
     ANIMAL CONSCIOUSNESS, ANIMAL PAIN AND SCIENCE".
     Oxford: Oxford University Press.  I would strongly
     recommend Rollin's book as a very well argued and
     documented scholarly work on this important issue.

[2] Burtt, E. A. (1924).  THE METAPHYSICAL FOUNDATIONS OF
     MODERN SCIENCE.  London: Routledge & Kegan
[3] See Flanagan, Owen's THE SCIENCE OF THE MIND (2n ed).
     Mass.: The MIT Press.  Provides for a good review of
     these issues.
        THE FALLACIES BEHIND THE PLANT PAIN ARGUMENT

     Many are destined to reason wrongly, others, not to
     reason at all; and others, to persecute those who do
     reason.  (Voltaire)