ENGLISH COMMENTARY
In ch. 9 he begins from the instances of unity in the physical elements. The natural science of his school held a vague anticipation of the theory of gravitation, at least in the elements Earth and Water: 'every pebble attracts every other pebble, though truly with a force almost infinitesimal.'[1] With this the Stoics, like most Greek physicists, held the false notion of the natural levitation of Air and Fire. Marcus here relates this to a primitive notion that Air and Fire are fluids, and obey similar laws to those of water. The movement to unification is only prevented by a force which was called 'tension'.
This uniting tendency becomes more obvious, as we mount the scale of Nature, in the social instincts of animals. There followed in the early history of man tendencies to union and society which even caused cessation of wars.
Highest of all is the cosmic sympathy which unites the widely sundered starry heavens;
Connexion exquisite of distant worlds,
Distinguished link in Being's endless chain;[2]
or to quote Sir Oliver Lodge: 'Things which appear discontinuous, like stars, are ultimately connected or united by something which is by no means obvious to the senses, and has to be inferred.'[3]
Finally (ch. 9. 3) Marcus observes that only reasonable creatures have forgotten this urgent law of common sympathy; but he continues, conforming his language to the teaching of Heraclitus, man cannot escape the principle of unity which controls the whole, Nature overtakes and masters him.[4]
This view of evolution is interesting because there is no trace, such as we find in some Stoical writers, of the age of gold. Marcus recognizes in the animal world a tendency to permanency of union in the social insects, in gregarious animals and in birds, but in man both unity and strife. He does not take the Epicurean view of war of all against all, but an intermediate position. With this early stage of society he appears then to contrast a later, where men have degenerated—'see then what now is coming to pass'; thus men, though reasonably endowed, have deserted the path that Nature marked out for them.
