3.  There are innumerable other paths of practical continuity among things.  Lines of influence can be traced by which they together.  Following any such line you pass from one thing to another till you may have covered a good part of the universe’s extent.  Gravity and heat-conduction are such all-uniting influences, so far as the physical world goes.  Electric, luminous and chemical influences follow similar lines of influence.  But opaque and inert bodies interrupt the continuity here, so that you have to step round them, or change your mode of progress if you wish to get farther on that day.  Practically, you have then lost your universe’s unity, so far as it was constituted by those first lines of influence.  There are innumerable kinds of connexion that special things have with other special things; and the ensemble of any one of these connexions forms one sort of system by which things are conjoined.  Thus men are conjoined in a vast network of acquaintanceship.  Brown knows Jones, Jones knows Robinson, etc.; and by choosing your farther intermediaries rightly you may carry a message from Jones to the Empress of China, or the Chief of the African Pigmies, or to anyone else in the inhabited world.  But you are stopped short, as by a non-conductor, when you choose one man wrong in this experiment.  What may be called love-systems are grafted on the acquaintance-system.  A loves (or hates) B; B loves (or hates) C, etc.  But these systems are smaller than the great acquaintance-system that they presuppose.

Human efforts are daily unifying the world more and more in definite systematic ways.  We found colonial, postal, consular, commercial systems, all the parts of which obey definite influences that propagate themselves within the system but not to facts outside of it.  The result is innumerable little hangings-together of the world’s parts within the larger hangings-together, little worlds, not only of discourse but of operation, within the wider universe.  Each system exemplifies one type or grade of union, its parts being strung on that peculiar kind of relation, and the same part may figure in many different systems, as a man may hold several offices and belong to various clubs.  From this ‘systematic’ point of view, therefore, the pragmatic value of the world’s unity is that all these definite networks actually and practically exist.  Some are more enveloping and extensive, some less so; they are superposed upon each other; and between them all they let no individual elementary part of the universe escape.  Enormous as is the amount of disconnexion among things (for these systematic influences and conjunctions follow rigidly exclusive paths), everything that exists is influenced in some way by something else, if you can only pick the way out rightly Loosely speaking,