Denial
"Denial is a defense mechanism' postulated by Sigmund Freud, in which a person is faced with a fact that is too uncomfortable to accept and rejects it instead, insisting that it is not true despite what may be overwhelming evidence. The subject may deny the reality of the unpleasant fact altogether (simple denial), admit the fact but deny its seriousness (minimisation) or admit both the fact and seriousness but deny responsibility (transference)."