Half-knowing
There is a strange and delightful little story about Zarathustra hiking along a trail passing through a lowland swamp. He stumbles upon a man 
concealed laying across the path. The one underfoot quickly rises cursing. Zarathustra in the confusion of the moment gives him a blow with his walking stick. Shortly the two calm down, and it comes to light that the man lying with one arm submerged in swamp water is a disciple of Zarathustra’s teachings. Both instantly warm up to one another, like two lonesome dogs who happen to find one another. The dog image is from Nietzsche. “Are they not both lonesome ones!”
In a short time the stranger explains his personal philosophy to Zarathustra.
Better know nothing than half-know many things!
Better be a fool on one’s own account
than a sage on other people’s approbation!
Does it matter if it be great or small?
If it be called swamp or sky?
A handbreadth of basis is enough for me,
if it be a basis and enough of a ground.
A handbreadth of basis: thereon one can stand.
In the true knowing-knowledge
there is nothing great and nothing small.
—-excerpt Thus Spoke Zarathustra
By Friedrich Nietzsche, The Leech p. 241
These few lines indicate that it is more important to know thoroughly and deeply, and the subject matter is not important. To half-know many things is sufficient to make a wide public appeal, to gain notoriety as a bon vivant, celebrity-hood. A through, deep knowledge of even a small, obscure object of interest is enough to provide a basis for a life, ground upon which to stand.
It turns out that the man lying concealed across the path was studying the behavior of the leech. His arm extended into swamp water, attracted leeches. He did not claim to have ultimate knowledge of the leech, but only of the brain of the leech! His domain was the brain of the leech. “How long have I investigated this one thing that here the slippery truth might no longer slip from me!” With his own blood he increased his knowledge.
Strangely my mind segued to the two recent Boeing 737-Max disasters which cost the lives of all passengers. Obviously the decision makers at Boeing knew too little about this plane. They figured that a legacy plane design that due to increased length, and the size of more powerful engines, a plane which tended to go nose-up to stall upon take off, —could be made safe with software programming. Enough knowledge to gain lots of new orders,–but not enough for the passengers on those two planes.
