Recent important historical shifts – including the end of the Cold War in 1989 and the global financial crisis of 2008 (and beyond) have firstly sparked, then reinforced, a growing crisis of confidence in explaining social events by political scholars. What is the purpose of political science or political analysis if it cannot predict, explain or understand the build up to monumental shifts? The traditional social ‘scientific’ explanations have been increasingly called into question by an ideational turn that has gripped political analysis in general, and ontological frameworks – from rational choice theory to discourse analysis – more specifically. To what extent do ideas and beliefs play a causal role in understanding social phenomena and political events?
The importance of ideas (or idéologie from which it derives) cannot be understated. The most significant contribution came from Peter Hall in 1989, in which he argues that:
Policymakers customarily work within a framework of ideas and standards that specifies not only the goals of policy and the kind of instruments that can be used to attain them, but also the very nature of the problems they are meant to be addressing. Like a Gestalt, this framework is embedded in the very terminology through which policymakers communicate about their work, and it is influential precisely because so much of it is taken for granted and unamenable to scrutiny as a whole. 
This conception of a policy paradigm suggests that policy-makers behave in certain ways grounded in specific rationales. It implies that cognitive shortcuts play a large part of political behaviour. It suggests, moreover, that actors behave to sustain their belief system at three levels (everyday change, modification of the paradigm, or transformation/replacement of the paradigm).  Whilst Hall’s work on policy paradigms is rather descriptive, it remains interesting because it offers a degree of understanding towards changes that occurred in 1989 (the end of the Cold War) and 2008 onwards (the global financial crisis).
This leads us to interpretivism, of which Mark Bevir and RAW Rhodes’ work have been instrumental to understanding the role of ideas in political events. Their framework of analysis is made up of three inter-related elements: i) ideas are beliefs; ii) beliefs are located within traditions (as ‘webs of belief’); and, iii) ‘dilemmas’ or problematiques within a web of belief are the cause of change. This is a logical framework, succinctly justified by Bevir and Rhodes themselves:
Different people adopt different beliefs and perform different actions against the background of the same social structure. Thus, there must be a space in social contexts where individual subjects decide what beliefs to hold and what actions to perform for their own reasons. 
In this context, all beliefs are the interpretation by actors of social phenomena, events or relationships; knowledge claims cannot evolve in a vacuum and without the interaction of others. The aggregation of beliefs become traditions – traditions which are purely contingent on the beliefs of actors, which makes them entirely constructed, yet equally binding, limiting, constraining ‘acceptable’ behaviour (the logic of appropriateness). Furthermore, beliefs are constitutive of all action and therefore explain political outcomes. Traditions locate beliefs which in turn produce action. This ontological commitment is very useful, because it builds on the idea of ‘thick description’ in order to discretely assess political phenomena. The overarching conclusion that this offers us is that objective reality is a myth (something which I’ve covered in a number of other blog posts, including here). Ontological reality is obscure, arbitrary and entirely pointless, which is rendered only meaningful through interpretation, or as Ernesto Laclau argues, through ‘wars of interpretation’.  
The nature of interpretivism entails a certain problematisation of truth, and truth-telling more specifically, which I have mentioned in other blog posts. The issue of truth-telling is hugely important in the debate on interpretivism, because the ontological framework suggests that articulating beliefs as ideas has the inevitable consequence of constructing truths, and engaging with the production of reality more generally. To incorporate the ideas of Veridiction, it follows that a more ‘discursively based’ interpretivism entails that, first, when ideas become adopted as beliefs, they become ‘truths’, and second, that agents are nothing more than their very own construction of truth under constant re-development and re-evaluation under ‘dilemmas’ or problematisations. In this way, truth-telling, or Veridiction, should complement an analytical approach to further comprehend the agent, the self and the reality that surrounds him or her. This links back to political analysis in the sense that it returns us to the issue of the nature of politics itself. Politics is the moment of rupture between traditions, beliefs and ideas; it is a clash where rival truths emerge which are fought out in the public sphere. It is why we see politics in so many areas of life, reinforcing further my argument that politics is a process (rather than an arena) and that depoliticisation and tribalism are both dangerous attitudes. 
To summarise somewhat briefly, what I have essentially tried to do here is weld together the idea of interpretivism, which stresses the role of ideas in political analysis, with that of Veridiction, which emphasises the fundamental importance of truth as an activity to construct the agent in itself. Specifically relating this back to ideas of policy-making is especially conducive because it enables us to build on the idea that policy paradigms are crucial in understanding how policy is made.  The ideational turn in political analysis over the past 20 years has proven highly fruitful and innovative in the sense that it has established the causally usefulness of ideas in explaining and understanding political events. The discursive angle of interpretivism adds ever-greater value to truth-telling that I have previously established, indeed, it widens out the possibility of the analytical approach to make critical knowledge claims based on Veridiction as a technique located within the ontological commitments made by Bevir and Rhodes.
 P. Hall (1993) ‘Policy Paradigms, Social Learning, and the State: The Case of Economic Policymaking in Britain’, Comparative Politics 25:3, p.279.
 Ibid., pp.279-86.
 M. Bevir and R.A.W. Rhodes (2003) Interpreting British Governance, London: Routledge, p.32.
 E. Laclau (1990) New Reflections on the Revolution of Our Time, London: Verso, p.182.
 This is a final nail in the coffin for any materialist view of politics (including Marxism) as well as purely agency-centred ones (including rational choice).
 To some extent, there is also significant synergy with Alan Finlayson’s idea of Rhetorical Political Analysis that seeks to render explicit political thoughts and ideas into actions. See A. Finlayson (2007) ‘From Beliefs to Arguments: Interpretive Methodology and Rhetorical Political Analysis’, British Journal of Politics and International Relations 9:4, pp.454-63.
 At the moment, for instance, we are still in a neo-liberal policy paradigm. Although the global financial crash of 2008 may have initially broken its confidence, the age of austerity that is winning in the UK, and across Europe more broadly (to a lesser extent in the USA), suggests that neo-liberalism has not died yet. For more on this, see C. Crouch (2010) The Strange Non-Death of Neo-Liberalism, Cambridge: Polity Press.