"Motion and force are our primary objects of experience and consciousness; and in terms of them all other less familiar occurrences may conceivably be studied and grasped."

“The waves of light are not anything mechanical or material, but are something electrical and magnetic—they are, in fact, electrical disturbances periodic in space and time, and travelling with a known and tremendous speed through the ether of space. Their very existence depends upon the ether, and their speed of propagation is its best known and most certain quantitative property.”

“All potential energy exists in the ether. It may vibrate, and it may rotate, but as regards locomotion it is stationary—the most stationary body we know: absolutely stationary, so to speak; our standard of rest.”

“It is rather remarkable that the majority of learned men have closed their minds to what seemed bare and simple facts to many people.”

“Death is not a word to fear, any more than birth is. We change our state at birth, and come into the world of air and sense and myriad existence; we change our state at death and enter a region of—what?”

“Life must be considered sui generis; it is not a form of energy, nor can it be expressed in terms of something else.”

“What properties are essential to a medium capable of transmitting wave motion? Roughly, we may say two: elasticity and inertia.”