Question

1. Is it permitted to read philosophy books that include discussions, arguments, and refutations regarding the existence of God, including attempts to disprove His existence (heretical books)?
2. Is it permitted to listen to songs about unrequited love / betrayal, such as Mizrahi songs?
3. Is it permitted to watch Hollywood movies when it is clear that they include women dressed immodestly?
4. Is it permitted to study secular subjects on the Sabbath and Jewish holidays (English, mathematics, etc.) for the sake of self-enrichment / study?
Thank you very much