Tractatus Logico-Philosophicus
In philosophy, Wittgenstein's ladder is a metaphor set out by Ludwig Wittgenstein about learning. In what may be a deliberate reference to Søren Kierkegaard's "Concluding Unscientific Postscript to Philosophical Fragments", the penultimate proposition of the "Tractatus Logico-Philosophicus" (translated from the original German) reads: