62 PHILOSOPHICAL SOCIETY OF WASHINGTON. 
of persistence in state of motion impressed; and (3) the distributive 
power of imparting and acquiring motion by trangfer, at minimum 
distance, which may be called vis partitiva, the result of which is 
Newton’s vis impressa. Matter thus comes into the world of phe- 
nomena by the simple presence of other matter, permitting the 
exhibition of these comparisons and interactions, involving the 
conditions of contiguity, distance, position, translation, direction, 
succession or sequence, and time-rate for the continuous increments, 
decrements, successions, and uniformities, all bound up in the com- 
pound variable continuity—motion. With motion and distance 
comes the dependent phenomenon—energy—active and potential, 
which should be a constant, the numerical units of mass being con- 
stant throughout immensity, provided the sum of the motions, 
potential and actual, be constant. This the dynamical theory de- 
duces from the fact of central force (for without force potential 
motion is ridiculous), and the thesis of the conservation of energy 
is a dynamical truth or nothing. It is therefore all the more ex- 
traordinary that certain kinetists, who reluct against central force, 
should have selected, out of all the manifestations of the universe, 
the variable and conditional product—energy—to be the one reality 
or objectivity, aside from the undefined hypostasis—matter—as a 
primordial simple fact at the basis of phenomena. It has been 
mathematically demonstrated by Mr. Walter R. Browne (London 
Edinburgh and Dublin Philosophical Magazine, January, 1883, p. 
35) that the conservation of energy is true if the material system 
is a system of central forces, and is not true if the system is any- 
thing but a system of central forces. In fact, the ordinary theo- 
retical proof of the principle of the conservation of energy assumes 
the forces acting to be central forces, 7. e., reciprocal stresses between 
units of mass, as recognized by Clausius in his Mechanical Theory 
of Heat. Moreover, the entire body of kinetists, who have aimed 
to supersede gravity or central force, have freely assumed an extra- 
mundane supply of motion and energy without regard to conser- 
vation, and it is notable that every hypothesis for this purpose yet 
broached involves the constant expenditure of work without re- 
covery, and postulates the accession of energy in infinite influx 
from some occult source, of which only a small portion relatively 
is available or manifest in observable phenomena, thus yiolating all 
three of the canons of philosophical ascription—true cause, sufficient 
