Philosophical knowledge is the knowledge gained by reason from concepts ; mathematical knowledge is the knowledge gained by reason from the construction of concepts.
With regard to philosophical metaphysics, I always see increasing numbers who have attained to the negative goal, but as yet few who climb a few rungs backwards; one ought to look out, perhaps, over the last steps of the ladder, but not try to stand upon them.
Alice came to a fork in the road. 'Which road do I take?' she asked. 'Where do you want to go?' responded the Cheshire Cat. 'I don't know,' Alice answered. 'Then,' said the Cat, 'it doesn't matter.