The general consensus seems to be that since men aren't women, they can't speak about or fully understand the issues pertaining to women. I once read an analogy that tried to equate this logic with someone telling a veterinarian that since he isn't a cat, he cannot speak about the issues pertaining to cats. But since veterinarians do speak about cat issues, then it is safe to assume that men can speak about women's issues as well. Does the analogy work? Can men speak about women's issues?

To start with the literal truth: Men can indeed speak about issues pertaining to women, because (some) men do speak about such issues, which proves that they can . The question is how authoritative, how credible, about those issues a man can be. I think that will depend on the issue. An appropriately trained male researcher can speak with authority about (for example) the long-term health effects of this or that means of female contraception. But if the issue is more "experiential" or "phenomenological" -- such as "What does it feel like to be a female victim of workplace sexual harassment?" -- then it seems clear that any male has at least a burden of proof to discharge before we should regard his statements as authoritative or credible. I'm not saying that this burden can't possibly be discharged, only that it exists. (Clearly, I assume that speaking credibly about whether a man can be authoritative on issue X doesn't require me to be an authority on issue X itself.) For my answer to a...

Is the cause of homosexuality purely a biological and not a philosophical question? Or is there room for philosophical explanation?

What counts as a cause is certainly a philosophical question, and although both laypeople and scientists often confidently talk about causes, philosophers are far from unanimous about the correct analysis of the concept of causation. It's a matter of considerable controversy: see, for example, this SEP entry . But if we achieved a precise enough and plausible enough understanding of cause and a precise enough and plausible enough understanding of the concept homosexual (perhaps easier but by no means easy), then I think the question of what causes homosexuality would be purely empirical rather than philosophical. It may not be a purely biological question (again, assuming we understand biological precisely enough), but I don't think it would be, at that stage, a philosophical question. Still, lots of philosophical work would need to be done before the question became well-enough understood to be answerable empirically. Or so it seems to me.