"We cannot observe external things without some degree of Thought; nor can we reflect upon our Thoughts, without being…"

"According to the technical language of old writers, a thing and its qualities are described as subject and attributes…"

"We unfold out of the Idea of Space the propositions of geometry, which are plainly truths of the most rigorous necess…"

"By speaking of space as an Idea, I intend to imply the apprehension of objects as existing in space, and of the relat…"

"A scientific writer of modern times appears to wonder that men did not at once divine the weight of the air from whic…"

"It is better to form new words as technical terms, than to employ old ones in which the last three Aphorisms cannot b…"

"Our assent to the hypothesis implies that it is held to be true of all particular instances. That these cases belong …"

"The system becomes more coherent as it is further extended. The elements which we require for explaining a new class …"

"Man, servant and interpreter of Nature, does and understands only as much as he has observed of the order of Nature, …"

"And so no force however great can stretch a cord however fine into an horizontal line which is accurately straight."