On Striker's Definition of Natural Law

It should be clear, then, why Striker's defininition of natural law is unsatisfactory. Here it is again:

The term "natural law" refers, it would seem, to the rules of morality conceived of as a kind of legal system, but one that has not been enacted by any human legislator. By contrast to human legal codes, the natural law is supposed to be valid independently of any formal procedures, and such that is cannot be changed. Besides, this law is supposed to provide the standards by which human legislation is to be judged--laws will be just or unjust depending on whether they do or do not conform to natural law. This is, at any rate, the concept of natural law that I'm going to talk about.

There are some vague terms in her definition ('valid', 'conform to'), but apparently, according to Striker, in order to be a proponent of 'natural law theory', one needs to believe that:

1. There is some such separate thing as 'morality', and
2. The content of 'morality' may be expressed as a system of rules, resembling a detailed legal code; yet,
   
3. Although this code is very detailed, it is the same everywhere and unchanging; furthermore,
4. Positive law is just if and only if it coincides with ('conforms to'?) this moral code.

Now, has anyone ever thought this? I don't think so. Yet, if not, it seems pointless to look for the origin of this idea.

Moreover, it then becomes trivially true that this idea would not originate in Plato and Aristotle, as they are not the origin of any idea that no one ever held. It's a bit too easy, then, when Striker argues that Plato and Aristotle are not the origin of 'the concept of natural law', since they did not think of morality as consisting of a system of rules!

I hope I have said enough to substantiate my point that both Plato and Aristotle are rather far from endorsing anything like a conception of a natural law--the idea that morality can be represented as a system of rules, and the virtue of justice defined as the disposition to abide by those rules.

But Striker thinks that the Stoics were the origin of the 'concept of natural law'? Yet did they think of morality as consisting of a system of detailed rules? Or if they are 'far from endorsing' anything like that, or explicating 'morality' in that way, then by parity they are similarly not the originators of the 'concept of natural law'.

It must be said that Striker fudges the point. She uses a severe standard when she considers the extent to which Plato or Aristotle would acknowledge moral rules, but an easy standard when she looks to the Stoics:

Chrysippus argued that following nature will consist in pursuing two primary impules that nature has given to human beings--the impulse toward self-preservation and the impulse toward sociability. The first will lead one to seek out and acquire things needed for survival, but also presumably for the full development of one's innate capacities; the second is considered to be the foundation of justice as an other-regarding virtue, and leads to caring for one's children and family first of all, but then ultimately for the welfare of all human beings as well. Concern for oneself and concern for other rational beings is supposed to result in a regular and orderly pattern of conduct that will exhibit a kind of harmony that accounts for the goodness of the universe as a whole.

So far, no detailed code of rules, but a couple of basic rules at best. As for general appeals to regularity and harmony, these may be found in Plato and Aristotle as well as Chrysippus. Striker continues:

Obviously, a lot of filling in will be needed to arrive from those two fundamental tendencies at a detailed set of rules of morality. For example, one needs to set out in detail what things will be needed for self-preservation or self-development, and what is required by concern for others. Also, it seems fairly clear, at least from a modern perspective, that the two primary impulses might lead to conflicts: what if what I try to do to preserve or develop myself turns out to involve actions that will harm rather than benefit my neighbors? How can one show that my concern for others will appropriately limit what I do to promote my own welfare?

These would clearly be questions that any code of morality akin to a legal code would have to answer, especially those questions that relate the private to the common good. Did the Stoics provide answers that suggest that morality consists of a system of rules? At this point Striker shifts attention to the different concept of 'following nature':

It is not clear that observation of nature will provide an answer to these questions--and in fact it seems that when the Stoics were challenged to give a reply that would show how following nature does lead to just and virtuous conduct in cases of conflict, they found themselves in considerable difficulties. But I cannot try to pursue these further questions here.

Elsewhere she cites De Officiis as developing a detailed code of moral rules of the sort she thinks the 'concept of natural law' requires. But doesn't that treatise contain simply an examination of various cases and examples, in light of some rules of thumb and intuitive appeals to the virtues? Striker acknowledges the difficulty:

But one has to admit, I think, that there is only a rather tenuous connection between these highly general observations about human nature and the often very specific rules of conduct we find in Cicero's De Officiis and the books of many later Stoics (from "Following Nature", sect. 4, "The Laws of Nature").

So if we say that Stoic theory licenses the postulation of a few general precepts that are naturally known from the observation of human nature, and then that practical reasoning is meant to fill in the details, from reflection on representative cases, differently so for different times and places-- Is it clear that nothing like this is in Plato, Aristotle, or other earlier thinkers?