 Here, however, arises a problem unique to humans. Whereas other animals have a single telos defining their nature (living the full life of a frog, including reproduction, being the sole telos of each frog, in the example used by Lear 1998), humans both have a distinctive human nature—arising from the unique capacity to use language to deliberate about how to act — and also share in the divine nature in their ability to use reason to understand the eternal and intelligible order of the world. Practical reason is the domain of ethics and politics, the uniquely human domain. Yet the political life is not necessarily the best life, compared with that devoted to the divinely shared human capacity for theoretical reason and philosophical thinking (compare Nicomachean Ethics I with X.7–9).