Eternal sin
In Catholic teaching there are six sins that blaspheme against the Holy Spirit. They are: Several passages in the Bible are frequently interpreted as referring to the unforgivable sin:
Catholic theology of sexuality
The Catholic Church disapproves of masturbation. Thomas Aquinas, one of the most prominent Doctors of the Catholic Church, wrote that masturbation was an "unnatural vice" which is a species of lust", but that it is a less serious form than bestiality, which is "the most serious", and than sodomy, which is the next most serious: "By procuring pollution [i.e., ejaculation apart from intercourse], without any copulation, for the sake of venereal pleasure [...] pertains to the sin of 'uncleanness' which some call 'effeminacy' [Latin: "mollitiem", lit. 'softness, unmanliness']."