When Horatio, Barnardo, and Marcellus happen upon the ghost of the king at the beginning of Hamlet, they are unsure what to think. The ghost looks like the deceased king of Denmark, but it could be an imposter. And if it really is the ghost of King Hamlet, why has it come? At first, they try to speak to the ghost, then Marcellus offers to "strike it with" his "partisan" (or spear).

The ghost disappears, and Marcellus explains how they "do it wrong" by "offer[ing] it the show of violence." Not only is it extremely unacceptable to be violent against one's king (who is "so majestical"), but this would have been a futile attempt. The ghost, after all, is "as the air, invulnerable," meaning that the spear would go right through it; the ghost is already dead and therefore indestructible, like the air. One could argue that, even while alive, most kings are considered to be indestructible, with absolute power.

Like so many other lines in Shakespeare's plays, this one has more than one meaning. It is important to note these double meanings whenever one can, for they give plays like Hamlet much more depth and can even be seen as a reference to Hamlet's indecisiveness.

Hamlet and his friends are undecided whether the ghost is real or whether it could be some agent of the devil or evil. As they discuss these possibilities, Marcellus suggests that it is wrong to inflict some sort of violence upon the ghost because it looks like a king--"majestical". Besides, trying to harm the ghost would do no good since it isn't vulnerable to anything that would harm a human being, such as a knife.

This is yet another example of how indecisive Hamlet is. It takes him some time to decide if the ghost is really his father.