"[Any] portion of corporeal matter which moves by itself when an impetus has been impressed on it by any external moti…"

"Special relativity has this in common with Newtonian mechanics: The laws of both theories are supposed to hold only w…"

"[O]ne of the most interesting aspects in Fabri's physics is the wholehearted adoption of the important principle of c…"

"The law of inertia has no known origin."

"One other test of gravity... is the question of whether the pull is exactly proportional to the ... and changes in ve…"

"The situation of everyday life which Kant used as an analogy to the inertia of matter is the contrast between matter …"

"I tell you that if natural bodies have it from Nature to be moved by any movement, this can only be circular motion, …"

"I mentally conceive of some moveable [sphere] projected on a horizontal plane, all impediments being put aside. Now i…"

"It seems to me proper to adorn the Author's thought here with its conformity to a conception of Plato's regarding the…"

"Second law of mechanics.—All change of matter has an external cause. (Every body remains in its state of rest or moti…"