Fallacies of omission occur when the speaker does not provide all of the necessary information for an argument, or when he misdirects others from the information that is missing.
An example of a fallacy of omission is the claim that slavery was not a problem of black vs. white, as many black people also owned slaves. This argument omits two important pieces of information. First of all, it does not provide the necessary statistics to prove either point (which would show that white people were mostly the owners, and black people the slaves in disproportionate amounts). Moreover, it does not take into account the fact that many black people owned slaves because it was the only way in which they could reunite with their family (ex. a husband buying his wife in order to be with her).
