Baba explained to the group about different mental states:
Subconscious experiences, although on the same plane, vary. Some are mere dreams, some visions, some the foretelling of the spending of impressions – but even the subconscious can be hallucinated. This is very interesting.
Now what is hallucination? Let us not play with mere terms. Let us see whether you really understand. It is not a dream; it is like delusion. The difference can be understood by examples. You sit relaxed and in your mind pictures of your home, your mother, family come to your mind, and you speak to the pictures that you can bring before your mind. This is imagination. You imagine yourself being in America – talking, eating, et cetera; that is imagination. Now, in this imagination you think that you actually see your home, your mother, family, et cetera, and feel their presence. This is hallucination.
As another example, I once asked a man to fast for forty days on water only. On the fourteenth day he saw strange things. He saw figures with ten heads and twelve hands speaking! He thought this was spiritual experience, but I assured him it was hallucination.
Now what is the difference between hallucination and spiritual experience? In hallucination you see things – extraordinary things – but you never feel blissful or peaceful. This is the only sure sign of differentiating between hallucination and spiritual experience. When it is hallucination, bliss and peace are not possible. In the state of delusion too, bliss and peace are not possible, but this confusion as to whether it was hallucination or spiritual experience does not remain. In hallucination you see figures, giant figures, or pygmies, et cetera, yet you doubt as to whether they exist or not. But in delusion you take things as existing which really do not exist. Hallucination is like a conscious nightmare!
–www.lordmeher.org, p2137