Nietzsche in what can be considered a critique of Cartesian reasoning at one point uses the identity of a flash with the lightning that 'produced it as a metaphor for famously saying that there's no doer behind the doing:
For, in just the same way as people separate lightning from its flash and take the latter as an action, as the effect of a subject which is called lightning, so popular morality separates strength from the manifestations of strength, as if behind the strong person there were an indifferent substrate, which is free to express strength or not. But there is no such substrate; there is no "being" behind the doing, acting, becoming. "The doer" is merely made up and added into the action – the act is everything. People basically duplicate the action: when they see a lightning flash, that is an action of an action: they set up the same event first as the cause and then yet again as its effect.
Are there any other answers to Nietzsche's question: if this is the case, who is speaking?
(this comes from the discussion of Mallarmé in The Return Of Language from chapter 9 called Man And His Doubles in The Order Of Things by Foucault on pages 332-333)