The March for Science on April 22 was billed as “the first step of a global movement to defend the vital role science plays in our health, safety, economies, and governments.” The Peoples Climate March, scheduled for the following weekend, has a broadly similar aim, although it's more sharply focused.

Scientists have been galvanized by the apparent rejection of the importance of science by the Trump administration—including the realities of climate science, alternative energy, and stem cell research—apparently justifies cuts in federal support for research in these areas.

This viewpoint also politically facilitates broader cuts in support for science and technology research and education, as evidenced by President Donald Trump’s proposed federal budget.

The problem in this fairly one-sided debate is its premise: that science is based on a set of assertions which scientists consider objective truths, but which are instead subject to interpretation.

But scientists don’t believe in objective truths either, nor do we as scientists base our scientific conclusions on them.

Continuously, in study after study, year after year, we insist on re-proving what would, under any ex-research context, be assumed to be fact. We don’t trust each other’s reports unless we ourselves can reproduce them, and we don’t care about what is called truth and what is not. We care about cause and effect, structure and function, correlations between events, and what logically accounts for those correlations.

I am a professor of chemistry at Northwestern University, and my research group publishes 15-20 papers per year in peer-reviewed scientific journals.

In a good scientific paper, many interpretations are considered seriously and either confirmed or discarded as illogical. Yes, there are some facts that may appear to be assumed in a particular study, but these facts were themselves derived from logical interpretations of previous observations.

One scientific “truth” is simply built upon others that have already been logically proven. If a scientist tries to base his interpretation of an observation on something that has not been logically proven, other scientists will not believe him.

Of course, there are conventions in science, just like there are conventions in everyday life. For instance, we have assigned what our brains process to be a certain color the name “red.” There is no meaning to that assignment except that it’s a commonly agreed upon name.

But, just as in everyday life, these conventions are only there so that all scientists have a common language. Conventions are not assumed facts; they are just conventions.

In addition to re-proving our conclusions, and every fact upon which they are built, in paper after paper, we routinely have to explain them to students. Students who work in our research groups start with very little basis or foundational knowledge that could be used to make assumptions or state objective truths. Therefore they must be convinced logically of every scientific conclusion.

And undergraduate students who are taking chemistry for the first time ask even more of us as scientists. They ask that we help them understand the principles of our fields in terms of their most basic daily interactions with the natural world, without jargon or formalism.

At a time in our cultural history with climate deniers and political pundits poking holes in what we know to be true, the more prudent action would be to understand that science, too, is based on the questioning of each and every fact. 

If we want to engage a larger fraction of the public in unbiased, apolitical discussions about the impact of scientific findings on our everyday lives, we, as scientists, need to explain ourselves and our thinking better. We should not just say climate change is a fact; they should call it a conclusion and state the supporting information.

Yes, we may be living in a post-truth world, but this world must include science and the task of scientific inquiry.

If you are a policy maker, don’t take our facts at face value, but at least ask us to prove our conclusions logically so that you can understand them. Denial of logic is a much more serious crime than denial of the existence of objective facts. And that is the truth.