When you have made a thorough and reasonably long effort, to understand a thing, and still feel puzzled by it, stop, you will only hurt yourself by going on.
If a man fasten his attention on a single aspect of truth and apply himself to that alone for a long time, the truth becomes distorted and not itself but falsehood.
Concepts which have proved useful for ordering things easily assume so great an authority over us, that we forget their terrestrial origin and accept them as unalterable facts. They then become labeled as 'conceptual necessities,' etc. The road of scientific progress is frequently blocked for long periods by such errors.
Some critics are like chimney-sweepers; they put out the fire below, and frighten the swallows from their nests above; they scrape a long time in the chimney, cover themselves with soot, and bring nothing away but a bag of cinders, and then sing from the top of the house as if they had built it.
There is, therefore, wisdom in reserving one's decisions as long as possible and until all the facts and forces that will be potent at the moment are revealed.