What is delusion?

What is delusion?

The Diagnostic and Statistical Manual of Mental Disorders defines delusion as:
A false belief based on incorrect inference about external reality that is firmly sustained despite what almost everybody else believes and despite what constitutes incontrovertible and obvious proof or evidence to the contrary. The belief is not one ordinarily accepted by other members of the person's culture or subculture (e.g., it is not an article of religious faith).

Delusion, by definition, requires someone other than oneself to disagree. Does that not lay the onus of calling delusion upon another? What of realities unknown to all else. The concept of God, for instance; the truth of which is conceivably unknown to all. What of aspirations? Hope? What of understanding of a complex system? Weren't all scientific discoveries first named delusion?

We can perhaps, look at delusion from a different lens; one of time. One can have delusional beliefs about the past, the present or the future. But before we get into that, we must establish that we are referring to delusion that is rooted in grandiose or persecution. Grandiose, of having power, knowledge, identity, love of an individual or a special relationship with someone. Persecution, in that injustice is being meted out to self. It is the readjustment of reality to suit one's sense of self; sometimes even desirable.

The negatives of delusion are fairly obvious; an altered picture of the reality, hideout from truth, frustration, most importantly failure to drive towards a better alternative.

The important question to answer then is, when is it desirable? This takes us back to the timing of delusion. The positive ramifications of a readjustment of the past in one's mind can be increased self esteem, better opinion of and hence better relationships with others and continued hope in an endeavour; of altering the present, an improved state of mind in terms of peace with self or the world in addition to the other positives related to the past; of the future: hope, continued belief in either oneself or an endeavour.

Are these really desirable? When? Are we in blanketing terms glossing over the real meaning of these concepts?

Is self esteem obtained by delusion, for instance, really self esteem?
Are improved relationships required? To what end?
What is hope? When is hope desirable?
What is peace of mind?