Others however maintain that for one man to be another’s master is contrary to nature, because it is only convention that makes the one a slave and the other a freeman and there is no difference between them by nature, and that therefore it is unjust, for it is based on force.
Politics (1:2:3(1253b))
Anybody can become angry—that is easy … but to be angry with … the right person, and to the right amount, and at the right time, and for the right purpose, and in the right way—this is not within everybody’s power and is not easy; so that to do [this] properly is rare, praiseworthy, and noble.
Nicomachean Ethics (2:9:2), p. 111
In crediting people with Liberality their resources must be taken into account; for the liberality of a gift does not depend on the amount, but on the disposition of the giver, and a liberal disposition gives according to [relative to] its substance. It is therefore possible, that the smaller giver may be the more liberal, if he gives from smaller means.
Nicomachean Ethics (4:1:19), p. 193
So here the question rises whether we have any reason to regard Nature as making for any goal at all, or as seeking any one thing as preferable to any other. Why not say, it is asked, that Nature acts as Zeus drops the rain, not to make the corn grow, but of necessity? … So why should it not be the same with natural organs like the teeth? Why should it not be a coincidence that the front teeth come up with an edge, suited to dividing the food, and the back ones flat and good for grinding it, without there being any design in the matter? And so with all other organs that seem to embody a purpose. In cases where a coincidence brought about such a combination as might have been arranged on purpose, the creatures, it is urged, having been suitably formed by the operation of chance, survived; otherwise they perished, and still perish, as Empedocles says of his ‘man-faced oxen.’
Physics (2:8), pp. 169-171 – an early statement of Darwinian survival of the fittest
– an early statement of Darwinian survival of the fittest
This only is denied even to God, the power to make what has been done undone.
Nichomachean Ethics (6:2:6)
Observation of the stars … shows not only that the earth is spherical but that it is of no great size, since a small change of position on our part southward or northward visibly alters the circle of the horizon, so that the stars above our heads change their position considerably, and we do not see the same stars as we move to the North or South … This proves both that the earth is spherical and that its periphery is not large, for otherwise such a small change of position could not have had such an immediate effect.
On the Heavens (2:14), p. 253
We must next consider whether or not anyone exists who is by nature of this character [belonging by nature to others] and whether it is advantageous and just for anyone to be a slave, or whether all slavery is against nature. And it is not difficult either to discern the answer by theory or to learn it empirically. Authority and subordination are conditions not only inevitable but also expedient [since slavery is economically necessary to support the city-state]; in some cases things are marked out from the moment of birth to rule or to be ruled.
Politics (1:2:7-8(1254a))
Usury [payment of interest] is most reasonably hated, because its gain comes from money itself and not from that for the sake of which money was invented. For money was brought into existence for the purpose of exchange, but interest increases the amount of the money itself (and this is the actual origin of the Greek word: offspring resembles parent, and interest is money born of money); consequently this form of the business of getting wealth is of all forms the most contrary to nature.
Politics (1:3:23(1228B)), p. 51