JOHANN HEINRICH LAMBERT

Proofs of the Euclidean [parallel] postulate can be developed to such an extent that apparently a mere trifle remains. But a careful analysis shows that in this seeming trifle lies the crux of the matter; usually it contains either the proposition that is being proved or a postulate equivalent to it.

The first object of my endeavours was the means to become perfect and happy.

I bought some books in order to learn the first principles of philosophy.

This hypothesis (Parallel hypothesis) would not destroy itself at all easily.

I understood that the will could not be improved before the mind had been enlightened.

I should almost therefore put forward the proposal that the third hypothsis (angle sum of a triangle less than two right angles) holds on the surface of an imaginary sphere.

I am undecided whether or not the Milky Way is but one of countless others all of which form an entire system. Perhaps the light from these infinitely distant galaxies is so faint that we cannot see them.

I bought some books in order to learn the first principles of philosophy.

The first object of my endeavours was the means to become perfect and happy.

I understood that the will could not be improved before the mind had been enlightened.

I am undecided whether or not the Milky Way is but one of countless others all of which form an entire system. Perhaps the light from these infinitely distant galaxies is so faint that we cannot see them.

I should almost therefore put forward the proposal that the third hypothsis (angle sum of a triangle less than two right angles) holds on the surface of an imaginary sphere.

This hypothesis (Parallel hypothesis) would not destroy itself at all easily.

Proofs of the Euclidean [parallel] postulate can be developed to such an extent that apparently a mere trifle remains. But a careful analysis shows that in this seeming trifle lies the crux of the matter; usually it contains either the proposition that is being proved or a postulate equivalent to it.