Dogen's advice is sound if you want to get along. It doesn't really apply if the aim is to get at the truth.

On the contrary, I believe that Dogen’s advice is sound if you want to get at the truth. His advice is more than a guide on how to get along, but also on how to abandon one's own egotistical biases.

In argument, all that typically happens, outside of the most extraordinary of circumstances, is that each party feels compelled to defend their own position and digs down deeper into their existing beliefs, and rarely finally convinces the other.

Think about it: have you ever really won an argument? Oh sure, you might walk away thinking “I really told him,” but did you actually convince him that your position was correct and that his was not? And wasn’t your conviction that you “won” based only on your own terms and set of beliefs, but from another point of view the other party might be perceived as the “winner?”

So in "argument" all that is really accomplished is a stubborn reinforcement of one’s own ideas and perceptions. To get at the “truth,” one needs to set all preconceptions and egoism aside. Argument and debate is not the way to do that. Dogen’s advice, as a part of the Buddha way, is.

After all, what is “truth?” Nothing can count as a reason for holding a belief except another belief. If justifying our beliefs can be only a matter of squaring them with other beliefs, then the sole criterion for a set of beliefs' being true is that they form a coherent web, a picture of knowledge known as holism. And different people interacting with the dynamic, ever-changing world might well find themselves with distinct but equally coherent holistic webs of belief - a possibility known as incommensurability. In such circumstances, who is to say what is true and what isn’t?

Reason can never produce truth, as reason is merely a product of one’s own individual web of beliefs, and a universal, absolute truth, by definition, transcends any one such web. The Buddha way, however, is to arrive at this universal, absolute truth by the dropping away of all egotistical viewpoints. Dogen taught that to study the Buddha way is to study the self, and that to study the self is to forget the self, and to forget the self is allow mind and body to drop away and directly experience all the myriad truths of the universe.

So if one’s aim is to arrive at the truth, argument should be set aside and we shouldn’t bother ourselves challenging diverging points of view. Instead, clear your mind of all preconceptions, and look at the world as it really is.