One appealing trait of the Cynics that they possess as a distinction from their contemporaries is their philosophy is inherently non-systematic. While Plato, Aristotle, the Stoics and even in some way Epicurus base their ethics on epistemological and metaphysical conceptions of the world, the Cynics are largely divorced from such things. They have a theory of human nature, yes, and proper human flourishing, but this stands completely within the realm of ethics, with normative claims about how we should live and who we should emulate – who possesses the traits we should value. Plato and Aristotle however, have complex theories and systems, categories and notions of forms that have been either disproven by science or skepticism (or both).
The Cynics however are more akin to the Ancient Skeptics in that they make no claims about the ultimate nature of reality; not only this, but they spend most of their time criticizing the normative claims and evaluations of their society rather than expressing their own attitudes and conceptions in a “positive” way. That is, they express what they believe by taking on a critical attitude, and expressing what they don’t believe or disbelieve in. There is a certain value to this. In today’s world, as in the world of the Cynics, there are people of any denomination, faith and philosophy who will express why you should hold position ‘x.’ The Cynics however, in a way, like Socrates, perform a type of ‘meta-ethics’ by evaluating the criteria of justification of those who base their views and values on the society they live in – those who accept the norms and “philosophy” of ‘x’ society because they are habituated into it. It could very-well be that a certain society is right about ‘x’ claim, but them being right and them having valid justification are two entirely different things. The Bible could be right that murder is wrong, but that in no way validates Divine Command Theory, and then it would be correct almost by “coincidence” like a conspiracy theorist who in his frenzied irrationality believes that aliens control his government and then by sheer happenstance he happens to be right. He didn’t provide proper rationale for his claims, but that does not mean that they are automatically untrue – just that he didn’t provide good (or any really) reason why we should believe that such and such is true.
There is also a type of “reductionism” or negation of claims in their asceticism, and saying that those with the least desires are the best well-off. Now, this is a positive assertion, but it is one that in its nature dispels our intrinsic “claims” that such-and-such is a value. That is, we instinctually desire and therefore value certain things, but what the Cynics (and others) are saying that such claims are not grounded. Just because we want something, or society tells us something is good, in no way demonstrates or validates that it is good. Once again, by “coincidence” it could be that they are correct, like the Conspiracy theorist who believes in an alien takeover who hypothetically is right. In a way, the Cynics do to what Nietzsche ultimately values (instincts/urges) what Nietzsche does (successfully or not) to everything but psychological characteristics and inclinations.
In a way the Cynics and the Skeptics are two-sides of the same coin. The Skeptics dealing intimately with the descriptive accounts of reality and what we can know about it (which is nothing in the absolute) and the Cynics with the grounding of normative claims and how we are to live; for the Cynics philosophy is intimate and personal. That is, though the claims are grounded in external standards regardless of the nomos of society, they are based on our human existence and need to be lived and experienced, not academically debated in Universities divorced from the world – they are not determined by society, but they should determine society.
Now, someone could make the claim that the Cynics are delving into the descriptive when they say that we are to live “according to Nature” that this is the normative delving into the descriptive; but to say this is to misunderstand the separation of the two. To say we are to live “according to Nature” is an entirely ethical (normative) claim. To describe Nature is to delve into the descriptive. Now, someone can reasonably make the claim that to say we should live “according to Nature” becomes an impossible task unless we have some accurate or reliable (valid) descriptive account of Nature. But as a metaphysical anti-realist I would then be compelled to say that to know “Nature” or the external world is in no way to know reality. But it does deal with the sense impressions of what we see in our external world, so it does deal with epistemology though not with metaphysics – so not with “descriptive” in the sense of grounding or defining reality with a capital ‘R.’
To make claims of the operations of the world and human behavior, but make no claims of the ultimate nature of things is the exact right view, in my approximation, to take. It conforms to both what we should do pragmatically and what we are capable of doing in our potential. To do otherwise is both to delve into the impossible and the unimportant.