User blog comment:PinkuNeko/Human transmutation./@comment-1618178-20130507204514

Well, if you are a male, you have sex with a healthy woman with no contraceptive systems during her fertile period and you'll have about 35% chance of making a human. Simple as that. XD

Now, if you're looking to make a human through alchemy, well, haven't you read the manga? Hohenheim pointed out to Ed and he proved it himself that it is impossible, since the connection between a soul and its body is unique and, therefore, unachievable by humans through alchemy. Even Homunculi are not humans, but merely a soul - that existed previously - trapped in a body, just like Alphonse.

In sum: you cannot MAKE a soul.

** Or course, that would be considering that Alchemy existed like FMA tells, which it doesn't. Alchemy really do exist, but it's NOTHING like FMA says it is. **