In practice, therefore, you must be more reality-oriented than a scientist, who has the help of the physical problem and the physical objects he is working with. Aim at being at least as reality-oriented as a scientist—which in this context means being exclusively focused on your subject.

primacy of existence

the universe exists independent of anyone’s awareness of it, that the function of consciousness is to grasp, not to create, reality, and that the absolutism of existence is what ought to shape one’s thoughts (and actions).

difficulty of accurate recognition

This difficulty of accurate recognition constitutes one of the most serious sources of friction in war, by making things appear entirely different from what one had expected. The senses make a more vivid impression on the mind than systematic thought.