This quote, which I found attributed to Isaac Asimow (1920-1992), sums up something I heard over tea in an academic staff room many years ago. We had been discussing how the university was allocating £200 to each member of staff for use in their research. Somebody noted that that provided mathematicians with a lot more, in terms of pencils, than it offered laboratory-based researchers.
"Why is it that you physicists always require so much expensive equipment? Now the Department of Mathematics requires nothing but money for paper, pencils, and erasers...and the Department of Philosophy is better still. It doesn't even ask for erasers."
...and what was he trying to say about philosophers?