The observation that science and politics make uneasy and often treacherous bedfellows is hardly revelatory. In science, all hypotheses must withstand the trial-by-fire of experiment; its methodology is self-correcting and objective, unconcerned with petty prejudices or personal conviction. Politics, by contrast, is deeply entangled with ideology – it is not bound to respect reality as science is, and thinks nothing of substituting convincing evidence for emotive rhetoric. And yet, when science and politics clash, it is all too often science that loses.

This is clearly seen in clashes between scientific evidence and economic liberalism, which is defined by the belief that economies should be founded along individualist lines, with minimal governmental regulation. Strong support for the free market and private property rights are identifying features. This latter axiom of faith states that those who have obtained property are free to exploit it as they desire, with no obligation to others. This right is considered absolute, and anything that would interfere with the property without consent – often even taxation – is considered an infringement.

With some variation, these principles form the basis of the political philosophy of many organisations, think tanks and even political parties, such as the Libertarian Party and Tea Party in the United States and Australia’s ruling Liberal Party. Yet often, these fiercely individualist and regulation-adverse philosophies clash with science, with hugely detrimental consequences.

Climate change illustrates this well, because despite overwhelming evidence of anthropogenic influence, there is a tendency for those with pronounced free-market views to reject the reality of global warming. The reason underpinning this is transparent – if one accepts human-mediated climate change, then supporting mitigating action should follow. But the demon of regulation is a bridge too far for many libertarians. Given that climate change affects everyone whether they consent to it or not, then unregulated use of natural resources infringes the property rights of others and is ideologically equivalent to trespass, so the tenuous property rights house of cards comes crashing down.

When faced with this ideological dilemma, free-market advocates often resolve the cognitive dissonance by simply rejecting the reality of climate change, rather than acknowledging that their axiom is fundamentally flawed.

I explored ideologically driven reasoning in a previous blog. Rejection of science seriously impedes climate action and denial is endemic in American economic-liberal sets, with the Tea Party being the worst offenders. Last year, when it snowed in Alaska in May, Sarah Palin exclaimed “Global warming my gluteus maximus!”, despite the fact that paradoxical cold snaps are predicted by climate-change models and do not contradict the finding that average global temperature continues to soar. Libertarian politician Ron Paul dismisses climate change as a hoax.

Of course the assertion that climate change is a myth is not a solely American phenomenon: Tony Abbot decried climate-change as “absolute crap”. Earlier this year he struck down the already limited carbon tax introduced to mitigate the damage, despite clear evidence that Australian average temperatures continue to rocket skyward.

The individualist anti-regulation stance of free-market advocates also has serious consequences for healthcare. As economist Paul Krugman explains in a recent column, disciples of Milton Friedman remain deeply opposed to the very concept of the US Federal Drug Administration, viewing it as needless intrusion by government. In Friedman’s opinion, without the FDA corporations would be kept from hurting people by fear of lawsuits and thus self-regulate.

The truth is that without external evaluation, it is difficult to work out the efficacy or side-effects of any drug. Ben Goldacre’s book Bad Pharma illustrates with copious detail that when pharmaceutical companies are obliged to do clinical trials, they are often reported in statistically devious, cherry-picked and wholly dishonest ways to overstate their treatments’ effectiveness. This is unsurprising, given the incentive of a private company is to maximise profit, with scientific integrity coming a distant second.

The expectation that private companies can be trusted to innovate health care is also misguided. While antibiotic resistance has been steadily increasing, for example, practically no new antibiotics have been developed in decades. A major reason for this is that despite the massive impact of antibiotics on mortality rates in the past century, they remain a low-profit product, typically used by a patient for only a short time. It is far more profitable to develop long-term medication for chronic conditions, and unsurprisingly this is what drug companies prefer to do.

This is the logical outcome of entrusting health research to private companies. It also means they can charge extortionate amounts for life-saving medicines. Free-market defenders may try to pin the blame on costly and needless regulation for driving up prices, but this argument is somewhat superficial, given that they are generally opposed to increased taxation and public spending on medical research, which could circumvent this vicious cycle. It also ignores the fact that drugs companies spend multiples of their research budget on marketing.

Another example is gun control. Many American libertarians decry any suggestion that regulations should be tightened, insisting people have the right to arm themselves to make themselves safer. But the statistics show this argument to be nonsensical: those who carry firearms, even for protection, are much more likely to be shot and increase the risk of death for those around them. These trends have been confirmed time and again in serious epidemiological studies, yet despite the very act of carrying risking the safety of others, the ideological position of individual rights trumps the facts for a sizeable contingent of the US population.

All of these problems stem from a clash between ideology and evidence. The ruthlessly individualist philosophy fetishised by the modern disciplines of Ayn Rand conveniently ignores the fact that humans do not exist in a vacuum, and that individual actions often have consequences for all. The mantra that profit is a panacea for everything and that personal rights trump collective good is frequently misguided and potentially disastrous.

This is not to dismiss the entire political philosophy as bunk, nor to imply all economic liberals exist in a state of abject denial, but we must be wary of allowing any political ideology to blind us to objective reality. Our individual rights must be balanced against the rights of others, which requires a pragmatic interpretation of political philosophies, and some softening of extremist outlooks.

While we may hold incredibly strong personal convictions, reality doesn’t care one iota for what we believe. If we persist in choosing ideology over evidence, this endangers us all.