This quote seems to point at a lot of Jeffersonian beliefs, most importantly a strong individualism, a belief in focusing on advancing towards a greater future, and an official form of secularism. To me this quote is quite sad as it seems to reek of pride and excessive notions of self-worth - the argument against this is that Jefferson is simply pointing out that blindly following tradition is regressive, but I think we see best why this is an unfortunate statement in how Jefferson describes the native population as being lesser humans because they continue their ancestor's practices. This is a very Western notion, to praise ingenuity and young striving individuals over the wisdom of elders, and to view with near pity the idea of following their way of life. This American notion is what has destroyed many cultures, such as the Ladakhi people who now send their children to Western schools where they are taught that farming is savage and that math and grammar prove one's superiority over others, which as a consequence has made the elders of the community feel inadequate and simply stupid. I wish Jefferson had a calmer and more respectful view of tradition and community, but he seems too full of pride and American Protestant virtues to be able to reconcile abstract ideals of progress with views of being at peace with nature.