Heraclitus, again, maintains, that “contrariety is expedient, and that the best agreement arises from things differing, and that all things come into being in the way of the principle of antagonism.” Empedocles, among others, in direct opposition to these, affirms, that “like aims at like.” These physical questions we will take leave to omit, inasmuch as they are foreign to the present enquiry; and we will examine such as are proper to man and concern moral characters and feelings: as, for instance, “Does Friendship arise among all without distinction, or is it impossible for bad men to be friends?” and, “Is there but one species of Friendship, or several?” for they who ground the opinion that there is but one on the fact that Friendship admits of degrees hold that upon insufficient proof; because things which are different in species admit likewise of degrees (on this point we have spoken before). Chapter III. Our view will soon be cleared on these points when we have ascertained what is properly the object-matter of Friendship: for it is thought that not everything indiscriminately, but some peculiar matter alone, is the object of this affection; that is to say, what is good, or pleasurable, or useful. Now it would seem that that is useful through which accrues any good or pleasure, and so the objects of Friendship, as absolute Ends, are the good and the pleasurable. A question here arises; whether it is good absolutely or that which is good to the individuals, for which men feel Friendship (these two being sometimes distinct): and similarly in respect of the pleasurable. It seems then that each individual feels it towards that which is good to himself, and that abstractedly it is the real good which is the object of Friendship, and to each individual that which is good to each. It comes then to this; that each individual feels Friendship not for what _is_ but for that which _conveys to his mind the impression of being_ good to himself. But this will make no real difference, because that which is truly the object of Friendship will also convey this impression to the mind.