"Even though problems such as these can often be solved without a method and can sometimes perhaps be solved more quickly through good luck than through method, nevertheless they might dim the light of the mind and make it become so habituated to childish and futile pursuits that thereafter it would always stick to the surface of things and would be unable to penetrate more deeply."
— Descartes, René (1596-1650)
(Rule 10, p. 35)
See Opuscula posthuma, physica et mathematica (Amsterdam: P. and J. Blaeu, 1701).
Not published in Descartes' lifetime. Dutch translation in 1684; published in Latin in 1701.