For the purposes of understanding science it is best to focus on “closed theories” – Heisenberg’s term for theories that are superseded. That’s because we understand the limits of closed theories, so a true evaluation of their content can be made.
This fit well with the old model of academia: focus on a canon of classics, not on the latest hot ideas. Such an education provided time for contemplation and understanding. The humanities were king then, with the arts and sciences following along.
That changed in the 19th century, with the spread of the the Prussian model of education. Universities were to engage in cutting-edge scientific research and teach the latest theories rather than the ideas of the past. The sciences were repositioned to the top of the academic hierarchy and “open” theories were promoted with their seemingly limitless potential to transform society. “It’s all different now” was born.
One problem was that old academic weakness: conformity. A school is not in the position to say “we don’t know” without making students wonder why they are there. Instead, what is taught as knowledge covers everything and is everywhere authoritative.
Academic conformity didn’t much matter when the canon was fixed and the debates focused on the fine points. But when the canon became open and the latest ideas were now in play, academic conformity sought a rapid end to scientific debate. The consensus was formed quickly and doubt silenced.
Science changed. (The humanities did, too, but that’s another story.)
Science today has become more like the old humanities: debate is about the finer points – not the larger questions, which were decided some time ago. Anyone who doubts this is a “science denier”.
The irony is that all the great scientists of past centuries were “science deniers” in this sense. Following the crowd rarely leads to great advances. Like the old Scholasticism arrayed against Galileo, the science establishment has ways to enforce conformity. Plus ça change, plus c’est la même chose.