Analyze Cleanthes' argument from design and Philo's critique of it. After reading both, do you find the argument from design convincing?

Cleanthes and Philo are two characters from "Dialogues Concerning Natural Religion" by David Hume, one of the most significant philosophers of the Enlightenment. It is notable that there are three main protagonists in this debate, who each represent different perspectives. Between the two aforementioned, Cleanthes is an avowed theist and, moreover, one who is arguing for a rational God who can be understood in human terms. Philo, on the other hand, argues that God is something so far beyond human understanding as to make any knowledge claims thereof impossible.
Cleanthes's argument for design is one that both results in and follows from that fundamental assumption—God is rational and, moreover, intelligible by human terms. Ultimately, it derives from the observation that the world seems to have a certain order to it. In a very Enlightenment-minded comparison, Cleanthes compares the world to a kind of machine, where everything seems perfectly balanced to the point where one has to assume it had to have had a creator. Moreover, Cleanthes asserts that this creator had to be rational and intelligent in order to devise such a project.
This is fairly typical of the design argument (it is not too different from the more famous Watchmaker analogy). Perhaps more interesting are the arguments that David Hume invokes to challenge it, some quite well known, such as the argument from evil—can we truly call God simultaneously good and all-powerful, given all the suffering present in the world? And if we can't, what does this say about Cleanthes's case for a rational God? But the most important and fundamental argument which tends to serve as Philo's cornerstone in his case against Cleanthes is his use of Humean skepticism.
Hume's contributions to philosophy are really centered around two key themes—empiricism, the idea that knowledge can only be gained through sensory data, and skepticism, the idea that ultimately, knowledge claims themselves are precarious, perhaps even illusory. Both of these cornerstones appear in the "Dialogues." Ultimately, Philo rejects Cleanthes's entire approach, arguing that any such suppositions are coming out of a position of ignorance. We have no experience of or insight into the nature of God, and Cleanthes, in making his argument from design, is doing nothing more than reading human qualities into realms it cannot speak upon. Philo contrasts these claims with those made from common sense or derived from scientific insight. In both cases, human knowledge is always inevitably derived from things people have actually observed or experienced, and it is only from that experiential, empirical level that any conclusions can have validity.
But this is just the beginning of Philo's dispute against Cleanthes. He attacks the analogy of the machine (which requires a creator) by offering other, very different analogies that themselves would render very different conclusions. For example, Philo asks, what if, instead of comparing the world to a machine, we were to compare it to something biological? Is this truly an inferior analogy—to say that the world is still closer to a biological organism, something alive, than it is to say it is comparable to a machine? But if we were to take that comparison as our starting point, then suddenly we need not look for a creator. Rather, we would seek out models of germination or birth to explain the world's origins.
This leads to your second question—how do these arguments impact the argument from design? Personally, I do think the design argument is suspect, especially in the manner Hume presents it. This entire mechanistic vision of the universe is grounded in Newtonian physics, which has been challenged by the rise of quantum mechanics and relativity. So, it begs the question: does any comparison between the universe (for we'd be talking about the universe if we were judging this question from a modern twenty-first-century perspective) and a machine even make sense anymore, given the current state of science? In any case, as to your question concerning the argument from design, I do think you would be better served by measuring the various arguments against each other and coming to your own conclusions as to which case is the stronger.