Brutus justifies his actions by comparing Caesar to a serpent’s egg. Explain how this is an example of a false analogy.

Analogies between human beings and animals aften prove to be false, for unlike animals (much less an egg) human beings have minds and wills rather than instinct.  In trying to consider reasons to participate in the plot against Caesar, Brutus tries to convince himself that though Caesar is not a tyrant now, he might become one, and so better kill him now rather than allow that to happen later. Brutus suggests that it is natural for a serpent to grow mischievous, and so it is better to kill it before it is born (in his egg) rather than later. Similarly, he argues, Caesar is a serpent in an egg--he has the potential to be mischievous, and so should be killed now, before that mischievousness (meaning evil) actually becomes alive.  The analogy is false because Caesar is born (not in an egg), and has not shown himself to be evil yet; he has not shown himself a potential serpent; and even if he had, what would be the shell? A pretense of good?  It doesn't make sense that someone who acts good has the potential of being evil so that we should eliminate him before he becomes so.  The analogy is false, but Brutus seems desperate to build a case to join the conspirators.