1 534. Some persons have contended that mathematics ought
to be taught by making the illustrations obvious to the senses.
Nothing can be more absurd or injurious: it ought to be our
never-ceasing effort to make people think, not feel.

COLERIDGE, S. T.

Lectures on Shakespere (Bohn Library), p. 52.

540. Remember this, the rule for giving an extempore lecture
is let the the mind rest from the subject entirely for an interval
preceding the lecture, after the notes are prepared; the thoughts
will ferment without your knowing it, and enter into new com-
binations; but if you keep the mind active upon the subject up
to the moment, the subject will not ferment but stupefy.

DE MORGAN, A.

Letter to Hamilton; Graves: Life of W. R.

Hamilton (New York, 1882-1889), Vol. 3,

p. 487.

Source: Memorabilia mathematica; or, The philomath's quotation-book - Moritz, Robert Édouard, 1868-1940