What makes science different?

I was once asked by a lawyer friend what science is, and what separates it from any other intellectual discipline? The question followed a philosophical discussion where I claimed that my friend, as a lawyer, had a tendency to decide upon his desired outcome and then search for the evidence to support it. Science, I explained, did things the other way round and based its outcomes upon a consilience of evidence. I had to think for some time about what differentiates science from other subjects, after all, it’s not the only evidenced-based subject. History for example, is bonded to documentation and archeology.  I came up with the following answer in the form of a thought experiment.

Imagine that it was possible to control-alt-delete and start human existence from scratch. In this new world our cultures would inevitably be different, our religions, our legal, economic and political systems all have a virtually infinite number of alternative options to choose from. The arts could have similarities or be wildly different (that's what makes it art). Historical events would certainly be different; we may or may not have fought wars and if we did, then they would be fought over different grievances than those in our own history. 

At some point in the new history, great minds appeared and the scientific method was developed. As science progresses so it uncovered the mechanics of nature, not necessarily in the same order as we did, but its discoveries would nevertheless be the same. Newton’s laws of gravity might have some alternative name, Slartibartfast’s laws perhaps, but those laws would be no different to the ones we know. The laws of chemistry would be identical and DNA would have the same molecular structure that rigidly obeys those laws. 

Evolution of species by natural selection would be figured out, perhaps bypassing Lamarckism, perhaps not. For science is not about making the laws of nature, science is a way of discovering them. The scientific method removes human subjectiveness and points us towards reality as best as anything we have found so far. Of all subjects science is unique in this respect. It simply discovers what is, irrespective of what we humans believe.

Surely we would, my lawyer friend argued, require a social and political system which allowed scientific enquiry to flourish? Without the freedom to challenge assumptions and authority, or without the liberty to ask questions, science would remain a stifled backwater.  On that, my lawyer friend and I can agree but that’s a whole new thought experiment.