1 is not prime, by definition. 2 is an unnatural prime, 4 is an unnatural prime, and 6 is an unnatural prime. All other natural primes cannot be unnatural primes.
For the real difference between humans and other animals is that humans alone have perception of good and evil, just and unjust, etc. It is the sharing of a common view in these matters that makes a household and a state.
Error is multiform (for evil is a form of the unlimited, as in the old Pythagorean imagery, and good of the limited), whereas success is possible in one way only (which is why it is easy to fail and difficult to succeed - easy to miss the target and difficult to hit it); so this is another reason why excess and deficiency are a mark of vice, and observance of the mean a mark of virtue: Goodness is simple, badness is manifold.
Perfect friendship is the friendship of men who are good, and alike in excellence; for these wish well alike to each other qua good, and they are good in themselves.
The ridiculous is produced by any defect that is unattended by pain, or fatal consequences; thus, an ugly and deformed countenance does not fail to cause laughter, if it is not occasioned by pain.
In practical matters the end is not mere speculative knowledge of what is to be done, but rather the doing of it. It is not enough to know about Virtue, then, but we must endeavor to possess it, and to use it, or to take any other steps that may make.
Special care should be taken of the health of the inhabitants, which will depend chiefly on the healthiness of the locality and of the quarter to which they are exposed, and secondly on the use of pure water; this latter point is by no means a secondary consideration. For the elements which we use the most and oftenest for the support of the body contribute most to health, and among those are water and air. Wherefore, in all wise states, if there is want of pure water, and the supply is not all equally good, the drinking water ought to be separated from that which is used for other purposes.
Conscientious and careful physicians allocate causes of disease to natural laws, while the ablest scientists go back to medicine for their first principles.