Key ideas in C.S. Lewis

Continuing to read James Como's C.S. Lewis: A Very Short Introduction I come to "Ten key ideas from Lewis's works," from which:

These are central to Lewis's thinking: many of his arguments are based upon them and they were central to his life. Omitted are orthodox Christian ideas (e.g. the Incarnation), as well as political ones (e.g. the danger of fetishizing equality: 'I'm as good as you').

Joy (Sehnsucht) is a longing conveyed by some image or memory or event that does not originate in any of those but comes through them. It is from a place beyond the senses and kindles a hope that there is Heaven, that Heaven is our home, and that we will return there. It is painful because nothing in this world can satisfy it, no matter how hard we may try to do so; it is sweetly painful because we can intuit its origin and our destiny.

Contemplation and Enjoyment (or At/Along), or knowing from the outside and from the inside, where a phenomenon (such as religious belief or being in love) may seem very different. We need both.

Chronological snobbery is the uncritical acceptance of our own intellectual climate, as though past beliefs or practices are useless simply because they came before us. A corollary is that our belief in Progress is misplaced: we must ask what it is we are 'progressing' towards. ....

Morality is objective, outside of any personal preference or perception and accessible to Reason. To be subjective respecting this Natural Law (the Tao) is to submit to those who have the power, especially the technological power, to enforce their preferences, leading to 'the abolition of man'. It merits obedience. ....

Others are "Subjectivism is poisonous," "Reason is objectively valid," "Imagination," "Quiddity," "Personhood," "Ultimate Reality."

James Como, James Como's C.S. Lewis: A Very Short Introduction, Oxford, pp.63-64.