As to what standard is used in this trial and error it is known in biology as “differential reproductive success”. A favored variation will have leave more offspring than a unfavorable variation.
This is what is observed in countless experiments on the ability of natural selection to shape experimental populations. If you turn up the heat on a population, those variations amenable to high heat have more offspring.
What “works” in nature is surviving and reproducing.
What “doesn't work” is dying before you reproduce, having sickly or few offspring, etc.
Detection of “purpose” is beyond the scope of science.
If I lose at cards then I see it as God's will.
An atheist may well see it as just random bad luck.
There is no scientific way to differentiate or discern between these two views.
Detection of “purpose” is beyond the scope of science.... If I lose at cards then I see it as God's will.... An atheist may well see it as just random bad luck.... There is no scientific way to differentiate or discern between these two views.
I'm having a little difficulty reconciling these two passages. It's clear that the world-class British polymath Francis Bacon banished final causes from science in the late 16th–early 17th centuries — which is where the scientific doctrine of methodological naturalism came from in the first place. Clearly your second statement reflects this understanding.
What's not clear is why you use the card game analogy as an illustration of purpose. A purpose, or end or goal or, as Aristotle called it, peras ("limit") is precisely what philosophers mean by a final cause. We enter the domain of teleology here.
In Metaphysics, Aristotle defined the final cause as "an end which is not for the sake of anything else, but for the sake of which everything [else] is." He adds, "So if there is to be a last term of this kind, the process will not be infinite; and if there is no such term there will be no final cause. Those who maintain an infinite series do not realize that they are destroying the very nature of the Good, although no one would try to do anything if he were not likely to reach some limit (peras); nor would there be reason (nous) in the world, for the reasonable man always acts for the sake of an end [purpose or goal] — which is a limit."
Aristotle thought that a limit is the necessary condition of rationality in action, that it is something inherent in reason. And as Eric Voegelin points out, for Aristotle, reason is embedded in the order of being, and it is the property of reason to have a limit. Now logically, there can be no “end” of anything that did not “begin.” That is, the limit cannot be the production of an infinitely regressive causal series: There must be a First Cause. — J. Drew and S. Venable, Don't Let Science Get You Down, Timothy, Lulu Press, 2007, p. 42.So you see, by banishing final causes, you also render questions of origin (first cause) irrelevant, as beyond the scope of the scientific method in principle. But I digress.
To get back to your point about "purpose" in a card game; i.e., you say the "purpose" is to win. And the distribution of the cards is random. By which you show by analogy that "purposeness and randomness are not opposites."
Opposites? Good grief, I wouldn't say that! More like dynamic complementarities by means of which all of Nature is constituted! That is, by means of the dynamical relation between that which does not change, and that which is capable of changing. (E.g., by way of analogy, the relation between the first and second laws of thermodynamics).
It seems to me that randomness by itself accomplishes nothing in an unguided system. And of course, the "guides" would have to come from the causes that science has expunged from its method. With first (formal) and final causes gone, all we have left are material and efficient causes. If science chooses to restrict its method to these, fine. But then please, do not blow up this restricted method into a full-blown cosmology of the universe.
Let's say we're participating in a poker game, allmendream. Your purpose in being there is "to win." My purpose in being there is to have an enjoyable evening with good friends engaged in a sociable game of chance. Which of our purposes is more rational?
When we think of purposeful activity, we normally think of intelligence working toward the achievement of novel goals. In poker games, there really are few ways that human beings can inject intelligence in such a way as to affect the outcome of the game. Usually there will be an opportunity for discarding and drawing new cards. Which each and every time simply amounts to hitting the "reset button" on the random distribution of the cards. Short of bluffing (or cheating, heaven forfend), there's little a human being can do to change the outcome of a game that is constituted by the way the next card just happens to fall.
I'm pretty sure Nature does not do business in this way. And if it did, there'd be no room for you or me in it. Free will would be a joke. We'd have nothing to do....
Just some thoughts FWIW. Thanks for writing, allmendream!