A subject has a sense to it which sometimes takes the people on the cutting edge out beyond the edge, into the space where Original Research, the stuff of which Professorships are made, lies. Mere Doctorates lie in filling in the gaps behind, this is about the heart of inspiration. That's verse 1.
OK, so once you've got a sniff of something out beyond the edge of known reality, the problem is testing whether it is real or not, whether one's imagination has created something of insanity. For that, you can perhaps keep one toe in reality, but it's only one proof, the thesis has to stand up to examination from every angle and for that you sometimes have to go back in time: the problem is that the birth of modern science threw out the baby with the bathwater, the correct bits in its own roots alongside the noise of superstitious nonsense. So older thinking can teach us truths, which is pretty much our stock in trade here. That's verse 2.
Verse 3 you've covered.