We think the universe is only for human beings. Nowadays our ideas have become wider, and our way of understanding things has become freer, but even so, our understanding is mostly human-centered, so we don't see or appreciate the true value of things. Most questions and problems are created by human-centered ideas. "What is birth and death." That is a very self-centered idea. Of course, birth and death are virtue or merit. To die is our virtue; to come into this world is also our virtue. We see how things are going, how everything is appearing and disappearing, becoming older and older, or growing bigger and bigger. Everything exists in this way.
So why should we treat ourselves in a special way? When we say "birth and death," we mostly mean the birth and death of human beings. When you understand birth and death as the birth and death of everything-plants, animals, and trees-it is not a problem anymore. If it is a problem, it is a problem for everything, including us. A problem for everything is not a problem anymore. Almost all of these questions come from a narrow understanding of things. A wider, clearer understanding is necessary. You may think that talking about this kind of thing will not help you at all. For a selfish human being, it may be hard to be helped.
Buddhism does not treat human beings as a special category. It is deluded and egotistical to put humans in a special category. Yet it is normal for humans to think that way, not reflecting within but seeking some truth outside themselves. When you look for the truth outside, it means the background is not big enough. You need to find some confidence within yourself.
The Sandokai says here that all beings have their own virtue or merit. As human beings, we have our own nature. Only when we live like human beings, who have a selfish human nature, are we following the truth in its greater sense, because then we are taking our nature into account. So we should like like human beings in this world. We should try not to live like cats and dogs, who have more freedom and are less selfish. Human beings should be put into a cage, a big invisible cage like religion or morality. Dogs and cats have no such special cage. They don't need any teaching or religion. But we human beings need religion. We human beings should say "excuse me," but dogs and cats don't need to. So we human beings should follow our way, and dogs and cats should follow their way. This is how the truth applies to everything.
If we observe our way, and dogs and cats observe their animal ways, it looks as if humans and animals have different natures. But although our natures are different, the background is the same. Because where we live and the way we live is different, the application of the truth should be different. It is like the way we use electricity. Sometimes we use it as a light, and sometimes as a loudspeaker. Human beings have their nature and animals have their nature. But even though our ways of expressing our natures are different, our natures have the same basis. That is the application of the truth. This is actually what Sekito is talking about. We should not be attached to the difference in usage, because we are using the same true nature, or Buddha nature in different ways. That is how to find the true nature within ourselves in everyday life.