This document discusses different philosophical perspectives on teleology and functions in biology. It begins by explaining Aristotle's concept of four causes, including the final cause. It then examines various views on where goals and purposes come from, including traditional and modern perspectives. The document analyzes different accounts of biological functions, including homeostatic, etiological, propensity, and relational accounts. It discusses problems with each view and debates around what constitutes the "normal" function. The overall summary is that functions can be understood in multiple valid ways for explanatory purposes in biology.

1. Teleology and functions

2. Teleology - life’s aspirations
It is a co rre ct po sitio n that “true kno wle dg e is kno wle dg e by cause s. ”
And cause s ag ain are no t im pro pe rly distribute d into fo ur kinds: the
m ate rial, the fo rm al, the e fficie nt, and the final. But o f the se the final
cause ra the r co rrupts than advance s the scie nce s, e xce pt such as have
to do with hum an actio n. Francis Bacon, No vum O rg ano n, aphorism 3

3. Ends, and domains of
explanation
• Human intention and technology (te chne =def “art”)
– Psychological/cognitive (design)
– Ethical
• Natural processes
– Cosmic purpose
– Physical processes (planetary orbits)
– Living pro ce sse s - we are restricting ourselves to this
• Naturalising goals, the modern program
– To find ways in which goals can be made natural
• Anthropomorphism (seeing the world as we see ourselves)

4. Telos, a goal
• Te lo s = Greek for “goal” (fulfilm e nt or co m ple tio n,
co nsum m atio n, e nd)
• Plato: Mind is the cause for everything (External
telos)
• Aristotle: “that for the sake of which” (Internal telos)
– Four causes: material, formal, efficient, final
• Christian thought: Providence
– God foreordains all and designed all
• The Great Chain of Being: the world must be full
(principle o f ple nitude )

5. Aristotle’s finalism
• Four aitia (usu. trans. “causes”, better
“explanations”):
– Material (that which is changed)
– Efficient (that which changes matter)
– Formal (that to which it is changed)
– Final (that fo r which it is changed)

6. Kant and teleology
• In the Critiq ue o f Judg e m e nt (1790) he argued that
teleology was necessary to explain things that are
“both cause and effect of itself”, particularly living
things (§64)
• His was a natural teleology following natural laws
• Distinguished g e ne ric natural purposes from
individualnatural purposes
• Influenced many later biologists

7. Goals and purposes - where
do they come from?
• Traditional view:
– Goal-directed: change is targeted to
attaining an outcome (an e nd)
– Goals come from:
• External source: God (Platonic teleology)
• Internal source: Inner nature (Aristotelian
entelechy)
• External system <Natural Selection?>

8. Goals and purposes
• Modern view (Pittendrigh/Mayr):
– Goal-directed systems (teleological)
• I go to the fridge [in order] to find milk
– Goal-seeking systems (teleonomic)
• My digestive system processes my milk
– Goal-attaining systems (teleomatic)
• I drop the milk due to gravity

9. The old and the new
Teleomatic,
or end-
resulting
Teleonomic,
or end-
directed
Teleological,
or end-
seeking
Teleological,
or end-seeking
Teleonomic,
or end-
directed
Teleomatic,
or end-
resulting
Co g nitiv
e
Functio na
l
Lawlik
e
Idealist MechanistPro ce ss
e s

10. Progress in evolution
• Inevitability
• Net progress ve rsus local progress
• Eliminating progress
• Social progress and biological progress

11. Summary
• Modern teleology inverts the older kind
• Biological teleology is a by-product of
adaptation
• Teleology is an explanatory strategy

12. Functions
What are the y g o o d fo r?

13. Why care ?
“The organic world is full of functions, and
biologists’ descriptions of that world abound
in functional talk.” [Philip Kitcher]
• What biological things are functional?
• Are they functional in the things themselves?
• What function do functions have in explaining
biological systems?

14. Naturalising teleological talk
• Functions used to mean “goals” or “goal-
oriented behaviour”
• We want, after evolution, to see goals as
natural results - evolution is not goal-directed.
• Can we speak of functions without thinking
they are imposed from outside biology?

15. Philosophical Approaches
• Conceptual Analysis - finding out how some
group uses a term. Useful for that, but tells us
nothing else
• Scientific Analysis - how a scientist o ug ht to
use the term relative to a theory (e.g.,
evolutionary theory)
• Metaphysical Analysis - the nature of existing
things, no matter how we use words or what
works in a theory

16. Functions in biology
• Three versions
1 . Ho m e o static (what keeps it like that)
2. Etio lo g ical(where it came from)
3. Pro pe nsity (what it will do in future)
And one compound version: the Re latio nal
account (1 + 2).
• Vestiges - what is a vestige?

17. Homeostatic functions
• AKA CausalRo le or Syste m s-analysis functions.
Var: Cum m ins functions, or Ho m e o static
Pro pe rty Cluste rs
• “Homeostasis” = “keeping the same”
• Something is functional iff it contributes to the
homeostatic maintenance of the organism or
system of which the function-bearing trait is a
component. [def]

18. Problems with Homeostatic
functions
• Seems to require a prior knowledge (that it is
interesting and needs explaining, e.g., the
heart), or
• Assigns functions to uninteresting things (the
function of clouds in the rain cycle)
• Hence needs an etiological account to restrict
it to interesting biological functions

19. Etiological functions
• AKA Selective Effect functions. Var: Wright
functions, or proper functions
• “Etiology” = account of the causal origin
• Something is functional iff the appearance and
maintenance of that trait in the lineage of
which the organism is a member is due to past
contributions to the fitness of that lineage [def]

20. Problems with Etiological
functions
• Not required to do a functional analysis (Harvey
on the heart)
• Relies on knowledge or knowability of the
evolutionary history of the trait
• Involves using a problematic concept - homology
• What is the “proper” function of things? (Acorns
and squirrels): “Normal” versus “normal”

21. Propensity account
• Something is functional iff it has a
propensity to contribute to the future fitness
orsurvival of the lineage ororganism[def]
• How do we know what something will
encounter in the future?
• Mystery definition: “fitness” in the future

22. Modern History Account, and
Vestiges
• Something is a function if it has been
selected for in the recent past.
• Things can be retained for a while even if no
selection in their favour (adaptation versus
adapted distinction)
• Something can have had a function, but now
doesn’t - a vestige
• Deselected for old function, newly selected
for new function

23. Selection for function
• Function can persist when selection is
relaxed
• Traits no longer adaptive are vestiges
(Sober: were adaptatio ns , are now no t
adaptive )

24. Selection for function
• Vestiges for one trait (A) can be co-
opted as functions for another trait (B)

25. Normality Problem
• Something is a function whe n?
• Is the function of acorns to reproduce oaks,
or feed squirrels?
• “Proper functions” - Millikan’s etiological
account. Normal ≠ average or modal.
Then what?
• Normal for the clade or species? Or
homeostasis of that organism?
Millikan - etiology

26. Relational Account
• Combination of etiology (E-functions) and
homeostasis (C-functions)
• Trait X’s function in organismOis F in
selective regime S iff having Xis S increased
O’s fitness in S. A C-function increases
fitness in S to the extent that it maintains O
until it can breed. [def]
• “Normal” is thus dependent on reproduction

27. Conclusion
• We can be pluralists and think there are
at least 2 functions - E-functions and C-
functions and they have different roles
in explanations
• Or we can be monists and think that we
can combine E- and C-functions

28. John’s view
• We may not have naturalised functions but
we can speak of explanations as being good
or bad representations of biology
• Functions are something that appears in an
explanation, not in the biology itself. The
question is: is it a g o o d explanation? If it is,
then it is a good function.