...one can hardly deny that mankind has a common store of thoughts which is transmitted from one generation to another.

What are numbers? What is the nature of arithmetical truth?

There is more danger of numerical sequences continued indefinitely than of trees growing up to heaven. Each will some time reach its greatest height.

The aim of scientific work is truth. While we internally recognise something as true, we judge, and while we utter judgements, we assert.

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

Arithmetic has began to totter.

...one can hardly deny that mankind has a common store of thoughts which is transmitted from one generation to another.