How plausible is Rousseau’s account of the state of nature? Was it ever possible for human beings to live essentially by themselves, or is the need for some kind of society a fixed aspect of their nature?

Does the state of nature require historical evidence, or do you agree with Rousseau that reason alone can assemble an accurate portrait? In other words, does it need to be factually verifiable to be philosophically true?

Rousseau’s depiction of humanity depends in part on assumptions about animals as operating fully in accordance with nature, with no need for artificial socialization. Is this an accurate way of looking at animals? If at least some kinds of animals behave differently from what Rousseau describes, does that cause problems for his depiction of humanity?