Freud and Rousseau take very different approaches when it comes to nature, culture, and the dichotomy that exists between these relatively simple concepts, at least on paper. Indeed, the main difference between the two is that both of these viewpoints take very different approaches to the role of culture in general. Freud, it is clear, believes culture to be a positive force because it serves to keep humans in line, while Rousseau believes the opposite, that culture is a negative force because it denatures people, keeping them from truly being themselves, affecting them personally.
Freud seems to take a somewhat more pessimistic viewpoint when it comes to humanity. He believes that it is in the very nature of man to be selfish and, by extension, destructive to virtually anyone who is not himself. This viewpoint also means that culture is a civilizing concept, in a sense, because it inhibits these natural human tendencies of selfishness, forcing people, in a sense, to behave altruistically, if it can even be referred to as altruism at that point. This viewpoint is also one that addresses the issue of "id," which formulates a tapestry of human emotions and motivations, believing them to be primarily antisocial and amoral, throwing many of the most important developments and philosophies of humans in general into question in the process.
In contrast, Rousseau believes that human nature represents the truest and most pure version of humanity in general and that this human nature is a positive concept that should be embraced. Progress of civilization, Rousseau believes, is one of the key reasons for why people oftentimes feel so alienated, and as such, avoiding this negative influence altogether would be the most effective course of action to take, even though this is oftentimes not possible. Rousseau also believes that happiness also comes from one being true to oneself, while Freud would no doubt question this,
Freud is famous for believing that the very nature of human beings is extremely self-destructive and that the only reason humans have been so successful recently is because of the growth of the culture. This makes culture one of the most important and beneficial constructs of humanity, at least according to Freud. Rousseau would, naturally, disagree strongly with this sentiment, as he is a strong proponent of the ability of humans to forge their own path in life. Rousseau also believes that humans are self-sufficient and are, at heart, good, at least in the most general sense. Rousseau also does not believe in the concept of the id in the same sense that Freud does, meaning that Rousseau's viewpoint on humanity is one that is also much simpler than that interpretation on the part of Freud. As such, it is clear that Freud has a number of interesting viewpoints, such as this concept regarding the self and why people are naturally selfish, that is not necessarily accurate within contemporary society. His viewpoints are also those that have largely been debunked by extensive research.
Of these two viewpoints, Rousseau is more agreeable not just because it is more simple than Freud's interpretation, but also because he takes a much more trusting and agreeable viewpoint toward humanity in general. Indeed, Rousseau believes, much more so than Freud, that people are inherently good, and that culture only serves to stifle this. As such, Freud's viewpoint is one that seems pessimistic by comparison, making it much more difficult to truly implement when one considers the numerous minute elements that can be observed within his viewpoints. On the other hand, Rousseau is a much stronger proponent of the ability of people to be, for lack of a better term, self-governing. This means that people are much more autonomous and effective than Freud would seem to give them credit for, and this aspect of Rousseau is one that is extremely agreeable and understandable. Furthermore, Rousseau is one who believes that civilization has begun something of a process of alienation, and this has had an overall negative effect on human civilization as a whole. In this regard, Rousseau is one who believes that people are able to succeed even by their own merits, which, again, formulates a much more trusting viewpoint of humanity.
Both of these viewpoints are those that cast humanity, in general, in very different lights, with one being more trusting of humanity, and the other, Freud, believing that humans are naturally going to be conniving and unable to truly be trusted in any meaningful way, which casts many of the findings of other psychologists into question in the process. As such, Rousseau is more agreeable, but both of these viewpoints are well-founded and have a large amount of applicability.