One of my basic positions as a philosopher, programmatic for my work on philosophy of mind, is that I don't accept a distinction between human nature and the rest of nature. I reject, for example, the view that language (or "rationality," or God's will, or "negation") somehow releases humans from the causal relations and physical explanations that we apply to the rest of the physical universe. But that's not to say that humans aren't very fancy natural beings, a point that I am sometimes accused of missing (in discussions of animal mind, for example) but that seems to me too obvious to mention. It's just that my opinion about methodology is that we won't figure anything out by making human distinctness axiomatic (like the linguists mistakenly do), we've got to get to human consciousness and thinking from non-conscious, non-cognitive origins. Otherwise we have explained nothing.
Like all good philosophical questions, the question about the extent and nature of human uniqueness is a simple one that quickly takes us into deep waters. And like most good questions about mind and consciousness, it is one that is addressed by the fantastically rich Buddhist tradition. One of the pivotal historical developments of Buddhism was the Tibetan Renaissance of the eighth century, when the rulers of Tibet, hitherto a land of war lords and warriors, were converted to Buddhism and subsequently invited scholars and holy men from India to build a Buddhist society, the founding of the "Tantric" tradition (tantras are methods, and the name refers to a heterogenous approach including various types of yoga, meditation, teaching and other practices). My thought today is about meditation and our concept of ourselves, and the experience of the Tibetans of the early classical period as a case of "civilization," if we think of civilization as including the emergence of this sense of humans as apart from the (rest of the) physical world.
To meditate is to become aware of consciousness. Like Descartes, Buddha tends to identify the self with consciousness (as distinct from the body), and like Descartes Buddha quickly gets to the distinction between consciousness and the contents of consciousness (I don't mean to say that Buddhism has exactly the same metaphysical problems of mind and body as the European tradition, but I don't romanticize Buddhism nor do I demonize all things Western: all just people). Elemental point: this "discovery" (creation?) of mind is an element in the emergence of civilizations, constitutive of a sense that humans have volitions and thus are not just (determined) things. Notice that traditional (in the West think: Pre-pre-Socratic) peoples tend to think that all causation is intentional (causes are volitions of gods and spirits), so locating mind in humans simultaneously gives rise to the idea of physical causation as non-volitional, non-mental causation. Whether any of this is a good or a bad thing I cannot say. I'd like to discover that the Buddhist tradition, that I love, somehow cuts through the mind-body problem in a simple way that the dumb old Europeans missed, but I cannot say that.