Language Point 18

Capture the fleeting. (Para. 6)
Meaning: Some of the good ideas exist for a short time, so do not let them fly away. Be careful that "fleeting" is an adjective. Do not confuse this with two other different words: "flee" or "fleet".
Here "the fleeting" is used as a noun, meaning "passing ideas".
Here are some examples of "the definite article the + adj."
the unconscious(Para. 3, Passage A): the unconscious mind 潜意识
the blind 盲人
the deaf 聋子
the sick 病人
the unemployed 失业的人
the blamed 被告