A religious basis doesn't make a moral philosophy any more reasonable (you can't argue real divine inspiration without proof). I am not sure if you even intende

A religious basis doesn't make a moral philosophy any more reasonable (you can't argue real divine inspiration without proof). I am not sure if you even intended to imply that, of course. A "scientific" moral philosophy is still rooted in some fundamental non-objective rule, of course, but that's not necessarily a bad thing nor does it affect its plausibility. One fundamental is that humans are separated from other animals[1] not just by self-awareness but also awareness of others — and the resulting effect of empathy. With this information, it can be argued that this ability bestows an obligation to care for others. A consistent moral philosophy can be built from that and other observations. [1] This could apply to equal or lesser degree to some other species but we have no way of verifying it currently.