Pretty commonly, when Zeus wanted to get it on with a lady forbidden to him (either by his marriage to Hera, or parental control, or virginal vows), Zeus took the form of something else to disguise himself. Sometimes this disguise was for the benefit of those who might be watching for his next infidelity, but sometimes it was to deceive the woman he wanted, grant her a false sense of security, and then do the deed once she was in his power.
One such instance was the rape of Callisto. But this time, Zeus pulled a different trick. He didn't take the shape of an animal, or come to her as her husband. Callisto was a sworn virgin, a nymph of Artemis. So what did Zeus do?
Seriously followers and friends, this is by far the most underhanded of Zeus's tricks in my opinion, and I find myself slightly outraged by even reading about it. Zeus took the form of Artemis herself in order to get close to Callisto, and then when he had her in his grasp, he took her virginity and impregnated her. A sworn virgin and devotee of a virgin goddess!
Oofda. I'm not even sure I can find a way to swing that into something less than terrible! Holy Buckets, Zeus!
Apollodorus (3.8.2) presents the story this way:
Now Zeus loved her and, having assumed the likeness, as some say, of Artemis, or, as others say, of Apollo, he shared her bed against her will, and wishing to escape the notice of Hera, he turned her into a bear. But Hera persuaded Artemis to shoot her down as a wild beast. Some say, however, that Artemis shot her down because she did not keep her maidenhood. When Callisto perished, Zeus [...] turned [her] into a star and called it the Bear.I'll say this-- if he approached her as Apollo, it's slightly less offensive. But notice here that nobody has minced words about the nature of Zeus' conquest. This affair was most definitely rape.
Bad form, man. Bad form.
The real tragedy of this whole situation is the fact that Callisto was the one who suffered for it, ultimately paying with her life. And this is also pretty typical of these kinds of affairs. Zeus sweeps in, has his way, and leaves the woman to deal with the consequences on her own. When Hera decides to go for blood, Zeus rarely prevents it, and why is Hera going after these women anyway, when it's Zeus who is the instigator?
What the behavior of the gods says about the treatment of rape in ye olden days and the culture of the Greeks is pretty awful. Granted, these were the gods, and as such their morality was-- well-- they weren't expected to behave in a civilized manner, it seems. Yet, in other instances we see the gods punishing men for cannibalism (Zeus, even), or smiting men for the murder of immediate family members. One moment, they are so reasonable in their behavior and expectation, their morality, and in the next...
In the next, Hera and Artemis are killing a young woman for the bad luck of capturing the carnal attention of Zeus, and suffering his imposition without consent.
I have to remind myself that we can not hold the divine to human standards, but I always kind of expect/hope that it's because the divine are something better and greater. In this case, Zeus and the Olympians prove me wrong.