Updated: Oct 15, 2022
Even superficial familiarity with the history of philosophy and ideas (especially from a global perspective) immediately reveals that over the last millennia human beings at all latitudes and in all contexts managed to get extremely convinced of the most various and diverse ideas. Sometimes becoming so convinced of their validity to be ready to die for them, more often leading others to die for them, quite always ending up in quarrels and disputes.
But as any first-year philosophy student would know, believing something does not entail that what one believes is true. One can be extremely certain of a completely false or mistaken idea. Just read the news. From this point of view, one might consider the notion of 'truth' as a device used to check the validity of beliefs. If I believe that p, it is still the case that p might or might not be true. In order for this latter truth-judgment to make sense, 'true' should mean something different and possibly independent from subjective belief. One option is that truth captures some form of correspondence between ideas and a subject-independent objective reality, an external world 'out there,' in which 'facts' can be established. But there are many other rival theories of truths on the market of ideas: coherence, holism, pragmatism, and so forth.
This seems to bring us back where we started. In order to keep in check the validity of my belief, I appeal to truth. But in order to establish what truth is, I need a theory of it, namely, yet another belief. The problem is not solved (pace what some philosophers might believe!) by introducing a third notion, 'justification' and claiming that knowledge consists in 'true justified belief.' Because we run again in the same problem of establishing what a good justification is, which eventually leads to creating more beliefs. But a net of well-arranged beliefs does not make any of them stabler, in the same way in which increasing the size of a house of cards does not increase its stability.
Unlike in ancient Greek thought, the discourses of the Buddha do not make any extensive epistemic use of the notion of 'truth' (sacca). Perhaps the most famous instance is in the discourse on the 'four noble truths' (SN 56.11). But there, the use of 'noble truth' is best interpreted as an emphatic locution to stress the otherwise more common indexical construction 'this [noble truth!] is suffering' (and so on). By pointing to this, the Buddha says of it 'suffering!' If you imagine this as a scene happening before your eyes, it would require no explanation, because the gesture of pointing would do the trick. When this becomes the oral report of that scene (and even worse, a written text), the rhetorical strength of the pronoun vanishes and requires backing up, which is provided by 'truth'.
Be that as it may, 'truth' is usually touched upon in the discourses in moral contexts, and especially in connection with the precept of abstaining from falsehood. In this domain, truth is presented as the fact of reporting things to others in the way in which they actually happened or are, without altering or modifying them for the sake of gaining some advantage or just tricking the audience. This usage is not enough to conclude that it presupposes an epistemic theory of truth as correspondence, even if the Sanskrit root of the term (sat) might point in that direction (given that sat can mean both 'being' and 'truth' and even 'good' or 'reality'). Without mentioning that the discourses dispense entirely with the sophisticated, and at points convoluted, debates on the 'two truths' (conventional and ultimate) that became widespread (and plague) later Buddhist disputes.
But the lack of an explicit theory is not just a gap or missing piece if there is a reason for not providing such a theory, and this is precisely what happens. In the complex 'Discourse on the all-embracing net of views' (DN 1), the Buddha articulates 62 'speculative' views, mostly about the nature of the self and the world. All these views are in fact beliefs, and their common ground is found in the conditioned co-origination of experience. In particular, the Buddha connects all these views to the process that leads from stimulation (phassa) to feelings and then thirst, appropriation, existence, and birth.
This means that one comes to believe this or that about the self ('the self is eternal' or 'the self is mortal' for instance) on the basis of how one reacts to stimulations within one's field of experience, and how one interprets them. Regardless of the particular shape of the resulting view, the emergence of this view is seen as a way of ensuring some form of control or appropriation of experience. In this sense, I believe that p, not because p is true, but because I want p. Belief is the epistemic expression of thirst. This is the reason why all speculative views (no matter how objective or dispassionate they pretend to be) are actually ideological masks for the same basic attitude of craving and appropriation.
It is well known that the Buddha usually dismisses speculative views. And in some discourses (especially in those contained in the Atthakavagga, e.g. Sn 4.11) he urges to avoid quarrels, don't engage in disputes, and in fact do not hold on to any view. But isn't this in conflict with the fact that the eightfold path (the fourth noble truth!) begins precisely with right view? No, it isn't. Why? Because right view as is a path factor, it is not presented as a belief one has to hold on onto, but rather as a direction towards which one needs to move. Remember that in the presentation of the four noble truths the Buddha was pointing at things. The path is the fourth thing pointed at: 'here, this is the path you need to take if you want to get to freedom.' There is nothing to believe about this, and believing anything about it won't produce the relevant effect (awakening), as as if you're asking for direction in order to get to X, just believing that 'this is the way to X' won't get you to X. You need to walk on that path, you need to undertake it, to travel through it. The path is not a proposition, it's a practice. Right view is not a speculative view, it is not even a 'truth' in the epistemic sense, it is just the ability of seeing how to get to the desired destination.
This does not entail that one should dispense entirely with all sorts of beliefs, nor that this might even be possible. In some cases, some beliefs might be more helpful and conducive to support practice than others. For instance, belief in rebirth is more conducive to arouse urgency than the belief in annihilation at death. And rebirth is a belief, since for any ordinary person, it is impossible to practice rebirth or know it directly in any way, one has to be told about it by another who believes it (or who says to remember it, in any case, this will remain within the domain of belief).
But again, the criterion to judge whether a belief is helpful, unhelpful, or indifferent is again how it contributes to support a form of practice that it is not, in itself, based on belief. The eightfold path is based on observation (of the workings and structure of intentionality), on effort (aimed at steering the process of intentionality in a way rather than another), and on understanding (on how one is able to interpret the results of practice and assess them in connection to the goal of increasing freedom, rather than reducing it). This is why the 'reality' (Dhamma) taught by the Buddha is considered 'fully visible' or perhaps 'synoptically visible' (sandiṭṭhika), visible all at once, before your very eyes (cf. e.g. SN 35.70 or AN 3.53).
Beliefs can be helpful or not depending on whether (and to what extent) they lead to a directly visible realization of the structural problems associated with intentions based on greed, aversion, and ignorance, and provide guidance to overcome and disband them, by creating more freedom, release, peace, friendliness. This has nothing to do with validating, justifying or verifying beliefs, but rather with using them as tools. A pragmatic criterion for usage, then, rather than a pragmatic account of truth itself. Adjudicating who is right and who is wrong is besides the point, uninteresting, and ultimately damaging (if for nothing else, at least for the waste of time that this effort would entail). One shouldn't be concerned with what people believe, but rather with where their practice (their way of living) leads.
In this way, one might follow 'right view' without having to believe in 'right view' or in any other view. 'And without appropriating any view, / the honest one gains perspective' (Diṭṭhiñca anupaggamma, / Sīlavā dassanena sampanno, Sn 1.8). So, without being confused and hindered by having to defend and hold on to this or that belief, one can actually see what is in front of them, and what is ordinarily overlooked, and deal with that directly. Thus, one goes beyond belief, and truth.