Jean-André Deluc to Christoph Lichtenberg (1798):
“I told you, mon cher Monsieur, that there is no one I prefer to talk physics with than you; because I’ve always seen that like me (if I dare say so) you love physics for itself; which is true of very few people. Some do physics to talk about it, or to make a reputation, or to get a job; but the feeling and love for the truth are rare.”
A quote from John L. Heilbron, Natural Philosophy, in Wrestling with Nature: From Omens to Science, eds. P. Harrison, R. L. Numbers, M. H. Shank, 2011, p. 173 – 199.