In today’s culture wars, people are eager to accuse their opponents of “weaponising values”. When commentators on the right invoke free speech to defend speakers they support, they are charged with engaging in a rhetorical sleight of hand, having “weaponised free speech”. Progressives argue that conservatives don’t particularly care about free speech, they just want to win a political point. Some have gone so far as to say that “it is time to stop assuming good faith in the free speech debate”.

But the rhetoric of weaponisation cuts both ways. Jordan Peterson has defined the left as “the ones who weaponise compassion”. As Peterson sees it, leftists claim that the wrongs inflicted upon the oppressed outweigh all other moral concerns, and that the state is justified in using authoritarian social policy to redress this. According to this view, progressive activism is underpinned not by true compassion but by a ruthless, bleeding-heart logic. Other commentators reiterate his suspicion. Left-wing “compassion” for oppressed people is a ruse; its real point is to justify progressive power-grabs and provide a smokescreen for classist bullying.

The rise of weaponisation-talk is a symptom of the collapse in co-operative good faith across the political divide. A value is “weaponised” when it’s invoked in bad faith, in an effort to peddle insincere political talking points. Often enough, such accusations are apt. A lot of political discourse is spin. But it is increasingly difficult to name and criticise instances of this without being drawn into a game of rhetorical brinkmanship.

One response to these worries is simply to embrace the warlike mood. A popular name for this position in modern political theory is “agonistic realism”. The agonistic view, developed by the Belgian theorist Chantal Mouffe, is critical of politics that is driven by a desire for consensus and an aversion to conflict.

In the agonistic view, the politics of conflict aversion requires people to remove or ignore deeply-held commitments. For agonists, political conflict isn’t something to fear. It can lead to welcome social change, and even when it isn’t productive – when it breeds anger and dysfunction – these things cannot be wished away. Politics is necessarily about facing up to a fight, and making the best of things in a combative world.

However, the position the agonists are attacking – one in which a stable political consensus can be built around a few core ideals, such as civil rights for all and a social welfare safety net – isn’t so flimsy that it can be brushed aside. The politics of consensus is a pillar of contemporary democratic society. Its hope is that instead of endlessly fighting, people with different worldviews can co-operate under an overlapping consensus in their ideas about what makes for a decent society.

The jargon I’m using to describe these ideas comes from the 20th century’s most famous American political philosopher, John Rawls, but some version of these ideas – a politics centred on the ideal of pluralistic compromise – has been espoused by nearly everyone who has sought to defend the combination of individual rights and egalitarianism that defines postwar Western democracy.

Perhaps those of us who feel uneasy about this rhetoric are simply expressing liberalism’s deeply ingrained – and arguably naïve – tendency for conflict avoidance? Perhaps, but even if agonists are justified in criticising liberalism’s conflict-avoidant tendencies, nothing is gained by a mode of political conflict in which every agreement has been pre-emptively sabotaged.

Political negotiation – whether it involves consensus-seeking or agonistic bargaining – cannot achieve anything unless the negotiators have at least some preparedness to listen. If good faith is undermined to the point where duplicity is assumed on all sides, politics is bound to become mired in a cold civil war, or worse.

At the same time, to criticise both progressives and conservatives for weaponisation is to risk lapsing into “enlightened centrism”, as it is sardonically called in some corners of the internet. The positions are not always equal. It is worse to defend inhumane immigration detention policies by claiming that opposition to them is weaponised compassion than to defend the cancellation of a debate as weaponisation of free speech. The imprisonment of children is worse than the silencing of heterodox opinion.

But this isn’t a competition. Compassion and free speech are both indispensable to a just society. The real problem with the rhetoric of weaponisation is that it tends to undermine these basic commitments.

The idea that progressives have weaponised compassion has bubbled up at the same time as an unwillingness, among many conservatives, to show a decent level of compassion for people suffering terribly at the hands of inhumane immigration and welfare policies. A suspicion of progressive appeals to compassion has hardened into an unwillingness to be compassionate.

Similarly, the insight that free speech is sometimes deployed as a cover for a more reactionary politics has given way, in some progressives, to a short-sighted hostility towards free speech itself. People who are appalled by the persecution of dissidents and religious minorities in authoritarian states at the same time rationalise their own side’s censorious actions by insisting that free speech is nothing more than an alibi for bigotry. This hostility only makes Peterson’s hyperbolic caricature of the left appear more credible.

This is the ultimate danger of the rhetoric of weaponisation – that it hardens us against ideals. Nothing will be gained by pretending that political discourse isn’t shot through with insincere, tactical moralising. But we should be looking for responses which don’t also encourage tribalism.

When we insist that our political opponents have turned some ideal into a weapon, we make it harder to see that those ideals persist nonetheless, and that the demands they make on us have not changed.

Robert Mark Simpson is a lecturer in philosophy at University College London. His research focuses on social and political issues and he has a particular interest in free speech.

This article is part of the Agora series, a collaboration between the New Statesman and Aaron James Wendland, Professor of Philosophy at the Higher School of Economics. He tweets @ajwendland.