"To study the Buddha Way is to study the self.The self Dogen talks about here is not ego in terms of egoism. This is the self as jinissai-jiko (all-interpenetrating self) that is the reality of life prior to separation into dichotomies such as self/other or subject/object.
Previously Dogen Zenji said, 'Conveying oneself toward all things to carry out practice-enlightenment is delusion'. Although the self is originally living the all-interpenetrating self, my brain produces all kinds of non-interpenetrating thoughts. Thoughts well up such as: 'I want money!' 'I want sex,' 'I want a higher position!' and so on. When we are pulled by such thoughts secreted from our brain, that is certainly delusion. And yet, even though such thoughts are delusions, the fact that delusive thoughts come up is nothing other than a function of the reality of life connecting with heaven and earth. 'To study the Budda Way is to study the self' means that we should study the self, which includes all heaven and earth.
Concretely speaking, we should accept everything as the contents of our 'self'. We should meet everything as a part of ourselves. 'To study the self' means to awaken to such a self. For instance, many people visit my house or write me letters. Many of these people talk or write about their troubles and anguish and ask for my advice. I never feel troubled by such requests. As soon as I am asked about such troubles, they become my own. I meet people and problems in such a way. As long as I have such an attitude, these problems are my own. And they enrich my life. If I reject other people's problems saying, 'That's not my business', my life becomes poorer and poorer. Therefore, to meet everything, without exception, as part of my life is most essential to the Buddha Way. This is what Dogen Zenji meant by saying, 'To study the Budda Way is to study the self'".