Geometry in every proposition speaks a language which experience never dares to utter; and indeed of which she but halfway comprehends the meaning.

Every failure is a step to success. Every detection of what is false directs us towards what is true: every trial exhausts some tempting form of error.

In order that the facts obtained by observation and experiment may be capable of being used in furtherance of our exact and solid knowledge, they must be apprehended and analysed according to some Conceptions which, applied for this purpose, give distinct and definite results, such as can be steadily taken hold of and reasoned from.

Conscience is the reason employed about questions of right and wrong.

There is a mask of theory over the whole face of nature.

But with regard to the material world, we can at least go so far as this;-we can perceive that events are brought about, not by insulated interpositions of Divine power, exerted in each particular ease, but by the establishment of general laws.

Astronomy is ... the only progressive Science which the ancient world produced.