I compare arithmetic with a ...

I compare arithmetic with a tree that unfolds upwards in a multitude of techniques and theorems while the root drives into the depths.
 Gottlob Frege

Quotes from the same author

The aim of scientific work is truth. While we internally recognise something as true, we judge, and while we utter judgements, we assert.
 Gottlob Frege
It really is worth the trouble to invent a new symbol if we can thus remove not a few logical difficulties and ensure the rigour of the proofs. But many mathematicians seem to have so little feeling for logical purity and accuracy that they will use a word to mean three or four different things, sooner than make the frightful decision to invent a new word.
 Gottlob Frege