Doctrine Quotes - page 36
In his curious tract on Stereometry, published in 1615, Kepler made some advances in the doctrine of infinitesimals. Prompted to the task by a dispute with the seller of some casks of wine, he studied the measurement of solids formed by the revolution of a curve round any line whatever. In solving some of the simplest of these problems, he conceived a circle to be formed of an infinite number of triangles having all their vertices in the centre, and their infinitely small bases in the circumference of the circle, and by thus rendering familiar the idea of quantities infinitely great and infinitely small, he gave an impulse to this branch of mathematics. The failure of Kepler, too, in solving some of the more difficult of the problems which he himself proposed roused the attention of geometers, and seems particularly to have attracted the notice of Cavaleri.
Johannes Kepler
Thy wisdom speaks in me, and bids me dare
Beacon the rocks on which high hearts are wreckt.
I never was attached to that great sect,
Whose doctrine is, that each one should select
Out of the crowd a mistress or a friend,
And all the rest, though fair and wise, commend
To cold oblivion, though it is in the code
Of modern morals, and the beaten road
Which those poor slaves with weary footsteps tread,
Who travel to their home among the dead
By the broad highway of the world, and so
With one chained friend, - perhaps a jealous foe,
The dreariest and the longest journey go.
Percy Bysshe Shelley