1. Matter is the merely passive or statical condition for the action of force.[333] The most fundamental condition or characteristic of matter, "perhaps its only true indication, is _inertia_."[334] "All that we can affirm of it is that it is the _recipient_ of impulse and of Energy."[335] All the attempts which have been made to reduce matter to a function or phenomenon of force have ended in failure. Motion necessarily implies a _something_ which is moved by the action of force. Even that most wonderful and subtile of all "modes of motion"--light--necessarily implies an entity which is moved. "The magnetic rotation of the plane of polarized light, discovered by Faraday, implies an _actual_ rotatory motion of something." "The seeing intellect," says Mr. Tyndall, "when properly focused, must realize this conception at last." Matter must consist of ultimate continuous atoms or molecules possessing inertia and capable of being moved in space. By virtue of its extension and inertia it can intercept force, transform force into energy, and transmit energy. The various forms of energy (heat, light, electricity, magnetism, etc.) are transformations of force resulting directly or indirectly from the interception of force by inert matter, and "all the phenomena of material nature result from the action of force _upon_ matter."[336] "Matter," says M. Claude Bernard, "does not generate the phenomena which it manifests. It is only the substratum, and does absolutely nothing but give to phenomena the conditions of its manifestation."[337] 2. Force is that which originates or tends to originate motion, or changes or tends to change the state of a body with regard to motion. It is not and can not be a property of matter. The doctrine that force is an attribute of matter is disproved by the fact of inertia. Inert matter can have no spontaneous power--it can not change its own state of motion or rest. Neither is motion capable _per se_ of producing motion. It is a fundamental axiom of natural philosophy that motion can not be generated by motion itself, any more than by the negation of motion. Inertness and exertion, passivity and activity, are contradictory attributes, and can not be affirmed of the same subject. To say that matter is inert, and at the same time that it can exert force, is to violate the law of non-contradiction to the uttermost.