[iii][1] We must therefore now see what is the purpose of human society as a whole; when we have seen this, more than half our work will be done, as Aristotle says in the Ethics.

[2] And to throw light on the matter we are inquiring into, it should be borne in mind that, just as there is a particular purpose for which nature produces the thumb, and a different one for which she produces the whole hand, and again a purpose different from both of these for which she produces the arm, and a purpose different from all of these for which she produces the whole person; in the same way there is one purpose for which the individual person is designed, another for the household, another for the small community, yet another for the city, and another for the kingdom; and finally the best purpose of all is the one for which God Everlasting with his art, which is nature, brings into being the whole of mankind. And it is this purpose we are seeking here as the guiding principle in our inquiry.

[3] Consequently the first point to bear in mind is that God and nature do nothing in vain; on the contrary whatever they bring into being is designed for a purpose. For in the intention of its creator qua creator the essential nature of any created being is not an ultimate end in itself; the end is rather the activity which is proper to that nature; and so it is that the activity does not exist for the sake of the essential nature, but the essential nature for the sake of that activity.

[4] There is therefore some activity specific to humanity as a whole, for which the whole human race in all its vast number of individual human beings is designed; and no single person, or household, or small community, or city, or individual kingdom can fully achieve it. Now what this activity is will become clear when once we clarify what is the highest potentiality of the whole of mankind.

[5] I say therefore that no faculty shared by many different species is the highest potentiality of any one of them; because, since it is precisely that highest potentiality which is the defining characteristic of the species, it would follow that one and the same essential nature was specific to several species; and this is impossible.

[6] So the highest faculty in a human being is not simply to exist, because the elements too share in the simple fact of existence; nor is it to exist in compound form, for that is found in minerals; nor is it to exist as a living thing, for plants too share in that; nor is it to exist as a creature with sense perception, for that is also shared by the lower animals; but it is to exist as a creature who apprehends by means of the potential intellect: this mode of existence belongs to no creature (whether higher or lower) other than human beings.

[7] For while there are indeed other beings who like us are endowed with intellect, nonetheless their intellect is not ‘potential’ in the way that man’s is, since such beings exist only as intelligences and nothing else, and their very being is simply the act of understanding that their own nature exists; and they are engaged in this ceaselessly, otherwise they would not be eternal. It is thus clear that the highest potentiality of mankind is his intellectual potentiality or faculty.

[8] And since that potentiality cannot be fully actualised all at once in any one individual or in any one of the particular social groupings enumerated above, there must needs be a vast number of individual people in the human race, through whom the whole of this potentiality can be actualised; just as there must be a great variety of things which can be generated so that the whole potentiality of prime matter can continuously be actualised; otherwise one would be postulating a potentiality existing separately from actualisation, which is impossible.

[9] And Averroes is in agreement with this opinion in his commentary on the De anima. Now the intellectual potentiality of which I am speaking is not only concerned with universal ideas or classes, but also (by extension as it were) with particulars; and so it is often said that the theoretical intellect by extension becomes practical, its goal then being doing and making.

[10] I am referring to actions, which are regulated by political judgment, and to products, which are shaped by practical skill; all of these are subordinate to thinking as the best activity for which the Primal Goodness brought mankind into existence. This sheds light on that statement in the Politics that “men of vigorous intellect naturally rule over others”.