Here's a hint. When someone makes a reference to something that was actively debated for decades, and you're not familiar with said debates, you should probably

Here's a hint. When someone makes a reference to something that was actively debated for decades, and you're not familiar with said debates, you should probably assume that you're missing some piece of relevant knowledge. https://plato.stanford.edu/entries/mathematics-constructive/ https://plato.stanford.edu/entries/mathematics-constructive/ is one place that you could start filling in that gap.