Traits and/or states

[Kirk Fitzhugh]

At 09:45 AM 11/3/03 +0100, you wrote:
>Dear Dr.Fitzhugh,
>thank you for your explanation. Now I believe that our original point (of
>dr.Deleporte and me) was correct.
>You seem to suppose 'states' and 'characters' to be qualitatively
>different in that states are (representation of) observations while
>characters are constructs (concepts, generalizationos...).
>My position was (and is) that even 'state' is a construct - similarly to a
>character. You are giving an example of observing a state "five digits"
>which contrasts with our unability to observe "number of digits". I would
>like to point that even "observing five digits" is a product of
>information processing, often very complex. The organismal body is not
>naturally split into distinct perceptions that would naturally form
>'states'. Our splitting of a body into perceptions is a mental process
>(sometimes unintentional) and the same body can be surely split into
>different "sets of perceptions" (or characters states). Perhaps more
>importantly, the observation of "five digits" is possible ONLY IF YOU
>ALREADY HAVE A CONCEPT OF "NUMBER OF DIGITS". (why not to observe that
>there are "some digits" or "a finger and 4 digits" or "more than 3 digits"...?)
>Hence:
>1. 'states' are indeed representations of observations but not a
>one-to-one translations of observations. A representation is already a
>construction process. You can (and it is well known from taxonomic
>practice) make several mutually intersecting perception/state/character
>maps of one organism with no straighforward decision rule for which one is
>"right" or "false".
>2. consequently, 'state' and 'character' have similar epistemic position
>and can be ordered with formal relations
>3. state/character distinction is a way how to hierarchize these
>constructs in a way to make them useful for phylogenetic analysis; it is
>not to say that another hierarchization/ordering is impossible

Dear Dr. Skala,

Thank you very much for your additional comments. Herein a brief reply.

"You seem to suppose 'states' and 'characters' to be qualitatively
different in that states are (representation of) observations while
characters are constructs (concepts, generalization...)." No, this is not
what I meant. What I have been claiming is that the distinction between
characters and states does not accurately convey our observations. My
saying, "The appendage of this individual has five digits," is an
observation statement. Since no observation statement can be theory
neutral, the statement is also a construct. More correctly, the statement
is a hypothesis about what exists. My ability to infer such a hypothesis is
due to my own set of background knowledge.

So, I do not disagree with what you have said regarding the conceptual
nature of observation statements. What concerns me is that the
representations of our observation statements are not accurately conveyed
by the distinction of character and state. What we observe are objects, and
our ability to discern such objects is by way of what can be referred to as
their properties, characters, traits, states of affairs, etc. We represent
our perceptual beliefs by the conjunction of those named objects with some
predicate language. An object, or even a part of an object, is therefore
not the same as a character; a state is not a subset of a character. There
are no hierarchical relations of properties since there can be no
properties of properties. The relations we speak of are those of objects
(or subjects) and their properties, characters, traits, states of affairs,
etc. (as predicates).

Thanks,

Kirk

-----------------------------------------------------
J. Kirk Fitzhugh, Ph.D.
Associate Curator of Polychaetes
Invertebrate Zoology Section
Research & Collections Branch
Los Angeles County Museum of Natural History
900 Exposition Blvd
Los Angeles CA 90007

Phone:   213-763-3233
FAX:     213-746-2999
e-mail:  kfitzhug at nhm.org
http://www.nhm.org/research/annelida/index.html
----------------------------------------------------