If you want to become a chemist, you will have to ruin your health. If you don't ruin your health studying, you won't accomplish anything these days in chemistry. Liebig's advice to Kekulé.
Justus von LiebigThe secret of all those who make discoveries is that they regard nothing as impossible.
Justus von LiebigWithout an acquaintance with chemistry, the statesman must remain a stranger to the true vital interests of the state, to the means of its organic development and improvement; ... The highest economic or material interests of a country, the increased and more profitable production of food for man and animals, ... are most closely linked with the advancement and diffusion of the natural sciences, especially of chemistry.
Justus von LiebigI have learnt that all our theories are not Truth itself, but resting places or stages on the way to the conquest of Truth, and that we must be contented to have obtained for the strivers after Truth such a resting place which, if it is on a mountain, permits us to view the provinces already won and those still to be conquered.
Justus von Liebig