Visions, hallucinations.

And he knew it was a hallucination.

But he was being ridiculous. This was a mere hallucination.

Two people don't share the same hallucination.

In my opinion, Elwood P. Dowd is suffering from a thirddegree hallucination.

That hallucination of mine... the one that everybody was having such a good laugh about?

There are other parts of the brain which are specifically involved with the recognition and hallucination of buildings and landscapes.

At best, he thought, it had to have been a hallucination a trick of the eye or the ear, perhaps, or his own mind working against him.

You realize that if even one event is proved to be a hallucination... then this whole experiment will be questioned.

I used to argue that you couldn't classify these tryptamines as hallucinogenic because by the time you're under the effects there's no one home anymore to experience a hallucination.