What role do ethics and motives play in making and applying laws?

Ethical considerations often guide lawmaking, but the legislature regulates behaviour and is not interested in motives. Only when the law is broken does a court weigh the motives. A law felt to be immoral must be changed through legal channels, not by disobeying it.

• Lawmaking: passing laws is often driven by ethical considerations. In Switzerland, parliament (the legislature) makes the political trade-off.
• Relief from case-by-case decisions: laws spare the courts (the judiciary) from having to decide every case from scratch.
• Legal certainty: laws make outcomes predictable, so people can plan.
• Motives: the legislature only regulates behaviour. The court looks at motives only after the law has been broken, e.g. when it sets the sentence.
• Immoral laws: they must be changed through the legal process, not by refusing to follow them.

Go deeper:

• Wikipedia: Separation of powers — why the legislature makes laws and the judiciary applies them.