"A person who seems superficially dull but has a sincere aspiration (bodhi-mind) will attain enlightenment more quickly than one who is clever in a worldly sense" (Shobogenzo Zuimonki, 2-20).
"Many ignorant people with bodhi-mind eventually regress. Intelligent people, though lacking bodhi-mind, eventually arouse the aspiration for the Way. There are many examples in this age to prove this. Therefore, first of all, diligently learn the Way without being concerned with whether you have bodhi-mind or not" (Shobogenzo Zuimonki, 5-5).
Dogen seems to be contradicting himself here, first saying that it is better not to be too intelligent and later saying it is better to be intelligent. Was he right the first time and wrong the second, or was he wrong the first time and right the second? Is it possible that he right both times, or that he could have been wrong both times? Could he have been neither right nor wrong? Or both right and wrong?
Is it possible that he was right the first time and neither right nor wrong the second time? Or possibly neither right nor wrong the first time, but wrong the second? Or wrong in the first statement and both right and wrong in the second? Or both right and wrong and simultaneously neither right nor wrong both times? Or partially right and partially wrong once and totally wrong the next, or right but also wrong while being wrong, while also being right, the first time, and, well, you get the idea.
The dharma transcends dualistic constructs of the mind like right and wrong. Dogen also said you should practice "without being concerned about right and wrong, without clinging to your own personal views."
"Never expect to obtain some reward for practicing the Buddha-Way. Once you have moved in the direction of the Buddha-Way, never look back at yourself. Continue practicing in accordance with the rules of the buddha-dharma, and do not hold on to personal views" (Shobogenzo Zuimonki, 5-2).