Not all utilitarian theories are committed to believing the additive property—“average utilitarianism” most famously. Trying to maximize human “virtue” strikes me as quite a different thing than maximizing pleasure/utility and not something I would call utilitarianism. But in general yes, total, act utilitarianism is belief in maximizing additive property x where x is something like pleasure, desires, preferences etc.
Not all utilitarian theories are committed to believing the additive property—“average utilitarianism” most famously. Trying to maximize human “virtue” strikes me as quite a different thing than maximizing pleasure/utility and not something I would call utilitarianism. But in general yes, total, act utilitarianism is belief in maximizing additive property x where x is something like pleasure, desires, preferences etc.