You really can't. They aren't laws of nature, but they are based on observation: "When I have two voices proceed in parallel fifths, it's as though one voice ceased to have an independent character. Unless I want that effect, I should avoid that." "When I frustrate a leading tone, it makes the harmonic effect less clear."
Schoenberg's system starts with the arbitrary: pick a tone row and use it! But there are rules based on observation there, too: if you use tonal constructions in atonal music, it frustrates the listener's expectations, so don't do that. The ear can recognize the rows when transposed, reversed, and altered by other techniques, so those are good. Serialism is less fully-developed and lacks the deep cultural background of tonal music, but it's not entirely arbitrary either.