Arguments about God
There is part of the problem--how do you define "end." We need to take a close look at that concept.How does the heart's origin being accidental imply it doesn't have a natural end?
In Aristotle's conception, of course, the "end" was the telos--a design, or a purpose, similar to that found within human creations. You of course remember his account of the four causes using the bronze statue as an example (IIRC, I think he actually used different examples for telos, and used the bronze castter only for the other three types of cause, but I'm going to go ahead and use the bronze caster all the way through).
* The material cause--what's it made of (in this case, the bronze)
* the formal cause--what form or shape is it made into (in this case, the shape of the statue)
* The efficient cause--the primary actor (in this case, either the bronze caster, or the art of casting bronze)
* The final cause--the end, the statue itself.
(I need to interject that "formal" cause is something else I reject, as I reject the existence of "forms," whether defined by Aristotle or Plato, but that is a topic for a separate discussion.)
Here I see another possible communication problem--this time, on my side. I was looking at "end" as "purpose," and ... the term is more complex than that. Yes, purpose is part of the concept, but not the entirety.
So ff we go to final cause. Aristotle's notion of final cause in nature depended upon the concept of characteristic regularity--I don't remember his specific argument, I fear, but he at least once made the comment "It takes a man to generate a man."
My first argument against this concept is that, through science, we have discovered that this "final cause" is noting more than the mechanisms of the material and efficient causes (I think this also dispenses with formal cause in nature, but as I said, that's a topic for a separate discussion). The characteristic regularity Aristotle cited is not caused by some metaphysical process: it is a natural outgrowth of evolutionary biology, and requires no driving intelligence to accomplish.
Secondly, it must be noted that Aristotle never proved that final causes exist in nature. Aristotle defended the concept by analogy, but to actually prove the case, he would have had to establish that nature demonstrates the existence of final causes as an independant argument, something he never does (and, if I remember correctly, explicitly acknowledges that he does not do this). His defense of final causes, however, gives his reason--if we do not examine a final cause, we leave unanswered an important question about the natural world. I contest that, rather than jump to the conclusion that a natural phenomena has a final cause, we need to realize that the question is only answerable through our preconceptions. If we believe that a designer existed, we will see design: if we believe that no designer exists, we will see accident--a fortuitous accident, to be sure, but an accident nonetheless.
Thirdly, it is trivial to describe and name a final cause for a human-constructed artifact: it is impossible to desscribe and name a final cause for a natural phenomenon. A case in point: yes, the heart pumps blood ... but this is not its only function. The heart also monitors the oxygen and pressure in the blood, keeps oxygenated blood separate from deoxygenated blood (in mammals, but not in all animals), sets the rate of firing, and set the sequence of firing (where the atria contract before the ventricles). Now, all of these are parts of the function of the heart, and it is easy to say that the "main function" of the heart is to pump blood, but that is a human reification--other organs have more complex functions. (Additionally, many hearts in "lower" animals do not pump "blood"--indeed, in most insects, the circulatory system has nothing to do with oxygenation.) Who is to say that "pumping blood" is the "final cause"? Perhaps the final cause is to deliver oxygenated blood to the rest of the body, or to collect deoxygented blood from the veins for delivery to the lung. No, the heart has so many functions that naming one specific function is reification. (I highly doubt that Aristotle would have approved of an argument for multiple final causes!)
I'm not thinking clearly enough to attempt a formal argument, so the above are informal (and most likely pretty flawed) arguments.
This is where we disagree. You may prefer an explanation that includes telos, but the existence of these phenomena can most certainly beexplained without them.I'm not saying that it has teleos therefore it has teleos, but rather certain behaviors and effects of things can only be explained in terms of teleos, therefore it has teleos.
But that leaves open the question of whether or not the purpose was planned, or accidental. If a thing has an accidental purpose, this excludes the possibility that it was designed. If a thing has a deliberate purpose, this implies (actually, necessitates) a designer. How do you discern if a purpose was accidental or intentional?...things are supposed to function for a purpose
There. I think that's clearer than my previous attempts.