I believe that these terms refer to a specific and deep form of delusional irrationality which needs to be carefully spelled out. However I don't think this is the typical way of understanding them. Which typical way instead, I take it, has it that they are perhaps rather contentless derogatory terms, at best placeholders for a variety of possible everyday epistemic distinctions - to do with consistency or accuracy or willingness to be challenged.
Take what Lisa Bortolotti writes about the irrationality of delusion in her pleasingly clear Delusions and Other Irrational Beliefs. 'What makes delusions pathological?' Lisa asks (pp. 259-260). 'Whatever it is' she says 'it is not their being irrational, because the irrationality of delusions is not different in kind from the irrationality of everyday beliefs.' (Lisa also has a helpful Youtube video here in which she makes some similar claims about psychotic delusion.)
And consider why Lisa says this. Delusions, she amply demonstrates (you will have to take my word for this) in chapters 2 - 4, are not all that different from non-delusional irrational beliefs in terms of their procedural, epistemic, or agential ir/rationality. (Procedural rationality: a belief is procedurally rational if it is well integrated, consistent, with the believer's other beliefs. Epistemic rationality: a belief is epistemically rational if it is supported by and responsive to evidence. Agential rationality: agentially rational beliefs guide actions appropriately (actions here including speech acts).)
Well yes, but this would only entail that delusions are not to be considered pathological because of their irrationality if ir/rationality were exhausted by the above three forms. And it is my contention here that there is a more fundamental form of un/reasonableness. And that this form is aptly described by terms such as 'un/hinged', 'out of / in contact with reality'. (I now take leave of Bortolotti to describe this foundational source of intelligibility before returning to her argument at the end.)
There is, it seems to me, a picture of our relation with reality that can far too easily guide yet also constrain work in epistemology. In this picture the mind is an inner domain and reality an outer domain. In the inner domain there are 'representational states', beliefs say, which come in networks. There are (or are not) relations of rational entailment etc. between these states and between them and the subject's actions and utterances. And then there is the further question of their representational fit, singularly and together, with the outer world.
Now I have no quarrel with this as a picture of certain aspects of the relationship between some of our beliefs and other beliefs or thoughts or the facts. But as a picture of the essentials, and especially the foundations, of our reality contact it seems, to me, to be rather hopeless. In fact I would instead want to urge that the obtaining of those beliefs that are aptly characterised as obtaining as a network of inner representations presuppose that the subject is already related to reality in a more fundamental way. So let me now sketch another picture.
In this other picture our fundamental comprehending grasp of our situation is not considered a matter of representation but rather of a living bodily practical immersed engagement with our environment ('being-in-the-world'). We can start to grasp its character by contrasting it with our 'representational' beliefs which are characterised, one could say, by a division of labour between meaning-grasping and truth-speaking; for such beliefs we can be said to know what we mean by what we say when we articulate them even when they are false. But there is (contra the sceptic and her epistemological opponent), when what we are having to do with is our most basic comprehending relation with our world, not obviously any such thing as my possibly being regularly mistaken that I have two hands, that the world is aged, that humans mainly live in families, that the world is populated with trees and flowers and insects, etc etc. Why? Because my knowing these things is not something supplementary to my grasp of the meaning of the relevant terms: meaning and truth are for me here of a piece. At the point of our engaged immersed reality contact, before mind has lifted apart from world to be its representing mirror, meaning and truth are inseparable. I cannot be mistaken because my grasp was not a take in the first place.
At the point of our reality contact, in which the mind is of a piece with reality, and in which reality itself grace-fully constrains and structures our understanding and is not being asked to answer to representations, we find what I will call 'the hinge'. The hinge is what embeds us - it is (to use the existential-phenomenological idioms) the locus of our 'originary transcendence' (Heidegger), the moment of our 'flesh' (Merleau-Ponty) - this fleshly juncture is itself the prior condition of possibility of our holding true or false beliefs. The hinge is our rootedness in the world, a rootedness which then makes for the logically later possibilities of representing and inference making. Making putative truth claims at said juncture of the hinge is accordingly either to be spouting nonsense or nothing more than our unwittingly showing off that we know how to use our words (sarcastic response to Moore's 'This is 'one hand'' ... 'Very good little fellow, well done...!'). Doubt at this juncture is simply narcissistic (since it tacitly supposes that we can muster up the meanings of those of our words used to articulate the doubt by ourselves, without a prior reliance on the embedding regularities of our ownmost natural and social environment to provide content from - as one could misleadingly put it (falling back momentarily into the misguided representationalist inner/outer conception of our basic epistemic situation) - without.
I said the hinge - but in fact there are I suggest many hinges, many junctures from which we are anchored to yet pivot off from within the world into the domain of representational thought where we can then ponder or imagine possibilities and get things right or wrong. Colour hinges, body hinges, passion hinges, animal hinges - different hinges for all the different sui generis domains of discourse (for all the different 'language games' (Wittgenstein) as we might put it)...
In psychotic delusion one or more hinges collapse. The mind accordingly becomes, well - unhinged. And it now starts to become impossible for the clinician - for any Other - to 'find their feet' with the psychotic subject. This is the psychotic 'break' as we call it.
When some particular domain of mind is hinged then, as I have been describing, we not only have the possibility of originary transcendence/being-in-the-world (the juncture at which truth and meaning are of an embodied piece) but also the derivative possibility of representational thought, of imagining things as or as other than they are - this possibility that much of the epistemological tradition mistakes as the fundamental situation for our reality contact. But when the mind is unhinged, that which was hinged - the representational mind - starts to float free. And as it floats free it accordingly denatures. The uprooted representational tree can no longer take up from the soil structure of being-in-the-world the vital normative water and nutrients it needs to inform and constrain its thought from underneath.
So what we are left with, in the end, is a domain of quasi-thought in which the distinction between the ideal and the real, the imaginary and the empirical, collapses inwards. The imaginary and the real start to bleed back into one another; genuinely representational thought falters as 'reality testing' (itself not to be confused with the far more developed, representation-presupposing capacity for 'hypothesis testing') fails. We may be tempted to say things like 'reality becomes subjectivised' or the 'inner world becomes objectified' (Sass) but really these formulations presuppose once again that what is broken is intact. For at this juncture what we really have is an unmooring of the mind from its embodied roots, an unmooring which, because of what the hinge provided towards the normativity of thought, impoverishes thought itself. Thought becomes unconstrained and accordingly becomes denatured. 'Ego boundaries' break and this now unhinged aspect of our world-relation is no longer 'libidinally cathected': these psychoanalytic formulations are ways of referencing the same fact.
To finish lets return to the question of the unreason of delusion. The options canvassed and rejected by Bortolotti would have it that delusional irrationality is a matter of having badly behaving beliefs. The kind of irrationality that I am considering here instead refers us to the intelligibility made possible by our rootedness in our world. A failure of rootedness cuts loose parts of the canopy of belief. There is no doubt that this uprooting will lead to knock-on effects in the relations of beliefs to one another, to the believer's thoughts and actions and to their worldly situations. Delusional beliefs will, accordingly, be irrational in just the kinds of ways achieved by many of our better rooted thoughts. Yet as Bortolotti concludes, psychotic delusions are not in this sense radically different from other irrational beliefs. But what I have been urging here is that there is a deeper form of reasonableness or intelligibility constituted by our basic epistemic relation - that of originary embeddedness - to our world. Bortolotti concludes that there is no distinctive irrationality to delusion; what I have instead been proposing is that the irrationality that is a distinctive feature of becoming unhinged is a result of a disturbance of our hinged installation in our worlds.
One form of rapprochement between Bortolotti's and my own position would be to save the term 'ir/rationality' for the kinds of procedural, epistemic, and agential considerations she canvasses, and to discuss un/hinged reality contact in other terms. I don't terribly mind if that's how things go. But more turns on this than the right name; after all, as I understand it, the point of Bortolotti's concerns with promoting a conception of delusions as a) beliefs which are b) irrational in ordinary ways is to offer an optimistic normalised conception of them to the clinician. And part of what I am claiming is that the unreason of delusion is more severe than is estimated by this optimistic conception. But perhaps some kind of compromise could be reached? Maybe, for example, we could make a distinction between irrationality and unreason, thereby saving the traditional conception of delusions as manifestations of profound unreason whilst yet ceding that their irrationality is not of a particularly damning sort.
1 nb I do not take myself here to be proposing a dressed-up version of a causal theory of representational content, in which the content of the mind is to be understood as provided for causally and, as it were, effortlessly, by a world external to it. This is for two reasons: first I am talking about constitution rather than causation; second I am deliberately eschewing the inner/outer picture, along with the idea of inner representations of an outer world. Having said this I don't mind if causality were to enter into the picture in some way or other - so long as it isn't to be thought of as an explanatory relation between merely externally related relata.