He likens it to a businessman's forecasts of company prospects; 100 % accuracy can't be expected, but you don't discount its value altogether.
飛雲山人用了一個比喻：算命就好比企管專家對企業未來的預測一樣，不大可能和實際發展百分之百吻合，但也不能因此抹殺它的參考價值。