Locke on Intellectual Inheritance and Progress

From the fascinating fourteenth chapter of John Locke's The Reasonableness of Christianity:

When Truths are once known to us, though by Tradition, we are apt to be favourable to our own Parts; and ascribe to our own Understandings the Discovery of what, in reality, we borrowed from others; Or, at least, finding we can prove what at first we learnt from others, we are forward to conclude it an obvious Truth, which, if we had sought, we could not have missed. Nothing seems hard to our Understandings, that is once known; And because what we see we see with our own Eyes, we are apt to over-look or forget the help we had from others, who shewed it us, and first made us see it, as if we were not at all beholden to them for those truths, which they opened the way and lead us into. For Knowledge being only of Truths that are perceived to be so, we are partial enough to our own Faculties to conclude that they of their own strength would have attained those Discoveries without any assistance from others. Knowledge is light in the mind, which we see and perceive: And whilst it is certain that they be our own eyes that see and perceive it, who shall perswade us that ours were not made and given us to find truth as well as theirs who had no other advantage but the luck to be before us? Thus the whole stock of Human Knowledge is claimed by every one, as his private Possession, as soon as he (profiting by others Discoveries) has got it into his own mind; And so it is: But not properly by his own single Industry, nor of his own Acquisition. He studies, 'tis true, and takes pains to make a progress in what others have delivered; But their pains were of another sort, who first brought those Truths to light, which he afterwards derives from them. He that Travels the Roads now, applauds his own strength and legs, that have carried him so far in such a scantling of time; And ascribes all to his own Vigor, little considering how much he owes to their pains, who cleared the Woods, drained the Bogs, built the Bridges, and made the Ways passable; without which he might have toiled much with little progress. 

A wonderful little passage.