On the Apollinian and the Dionysian.

[Sauwelios]

In the opening sentence of chapter 2 of The Birth of Tragedy, Nietzsche speaks of the Apollinian and the Dionysian as "artistic powers [...] that burst forth from Nature itself, without mediation by the human artist". This is to say that Nature, not the human being, is the artist here. And in a posthumously published writing from the time of The Birth of Tragedy, titled The Dionysian Worldview, he says:

Whereas [...] the dream is the play of the individual human being with the real, the art of the sculptor [Bildner, literally "image-maker"] (in the broader sense) is the play with the dream. [...] As long as the statue is still hovering as a fantasy image before the eyes of the artist, he is still playing with the real: when he translates this image into marble, he is playing with the dream." [DWV 1.]

By "dream" Nietzsche also means "daydream". Now according to him, it is Nature which causes the human being to (day)dream. And to (day)dream means to play with the real. For whatever I may (day)dream of, my (day)dreams are informed by my experiences in waking life; but I'm not looking at the information seriously, trying to see my experiences as they really are, but playfully, making of them whatever I (subconsciously) want.

Likewise, to sculpt or, more broadly speaking, to make Apollinian art means to play with the dream. For in making Apollinian art, I'm not looking at my dream-image in disinterested contemplation, but am making of it what I want, for example a sculpture. My dream-image has become a means to my pleasure in sculpting, just as earlier my life-experiences had become means to my pleasure in (day)dreaming.

Now whereas the (day)dream is Nature's Apollinian art, intoxication is its Dionysian art. Thus Nietzsche writes:

[When intoxicated,] The human being is no longer an artist, he has become a work of art, he walks as rapt and exalted as he saw the gods in the dream walk. The artistic force of Nature, no longer that of a human being, reveals itself here: a nobler clay, a more valuable marble is here kneaded and hewn: the human being. This human being formed by the artist Dionysus is to Nature as the statue is to the Apollinian artist.
Now if intoxication is the play of Nature with the human being, then the creative act of the Dionysian artist is the play with intoxication. [ibid.]

According to Nietzsche, it is Nature which causes the human being to be intoxicated, just as it causes him to (day)dream. For not only is "the narcotic drink" a gift of Nature, but there's also another major cause of intoxication, namely "the mighty approach of Spring, which joyfully permeates all of Nature" (BT 1). Now by intoxicating him, Nature plays with the human being, that is, it makes something out of him, by enrapturing him and exalting him. So "This human being formed by the artist Dionysus is to Nature as the statue is to the Apollinian artist." For just as the sculptor, who is an Apollinian artist, transforms a block of marble into a statue of a god, for example, so Nature, who is the artist Dionysus, transforms a human being into someone who "walks as rapt and exalted as [...] the gods in the dream".

Now comes the most complicated part. For when speaking of Apollinian art, Nietzsche had said:

Whereas [...] the dream is the play of the individual human being with the real, the art of the sculptor (in the broader sense) is the play [of the individual human being] with the dream. [DWV 1.]

The dream is Nature's Apollinian artistic power (see the first quote above). Likewise, intoxication is Nature's Dionysian artistic power. So now we should expect something like this:

Whereas intoxication is the play of Nature with the human being, the creative act of the Dionysian artist is the play of Nature with intoxication.

But Nietzsche means that the creative act of the Dionysian artist is not the play of Nature, but the play of the human being with intoxication... So why does Nietzsche suddenly shift from Nature, a.k.a. the artist Dionysus, to the individual human being? The subtlety is that, in a way, he does not. For the Dionysian human artist is the human being who can somehow put himself in the place of Nature, of the artist Dionysus... Thus Nietzsche says:

[I]t is somewhat similar to when one dreams and at the same time perceives the dream as a dream. So must the votary of Dionysus be intoxicated and at the same time be lurking behind himself as an observer. Not in the alternation of sober-mindedness and intoxication, but in their existing side by side does Dionysian artistry show. [DWV 1.]