If we order some human beliefs among delusions – and religious beliefs constituted the main objects of such interpretation -, we should know what human enterprise has no traces of delusion.
The claimed possession of truths is not sufficient for excluding delusion. The healthy enthusiasm of discovering and possessing truths is stained by the delusion that they can belong in an essential way to those that found them.
Nevertheless, nobody can claim that some truths constitute him like some organic features. The truths lay in their truthfulness as bodily parts in their organic position.
At most we can deludedly convince ourselves that truths may be dragged out from their truthfulness for populating our lives consecrated to discover them.
In this case, truths and the beliefs generally deemed to be delusions cannot be clearly separated. The success of supposed objective truths over delusional beliefs is just a result of the fact that someone who claims the possession of truths is rarely worried by the unrest of someone who believes in realities that overcome him. Thus, the possessor of truths has the easiness of drawing clear-cut limits between truths and delusions.
[There is not a peculiarity of Plato’s philosophy that he allows mythical beliefs to interweave with the searching for truths never claimed to be possessed.]