I was in Ottawa this week for a few days, doing some intense research and writing at St. Paul's University. It has, by the way, a wonderful theology collection.
I spent a bit of time thumbing through the 1960s theological collosus', Karl Rahner's, works, especially his multi-volume Theological Investigations. Rahner is very smart, but very boring and, in my humble opinion, not all that orthodox. I said that throughout my students days and continue to say it, to the dismay of most of my teachers.
But a few thoughts.
1. Mode. Rahner writes as a fundamental theologian. All his writings address topics from that perspective. You need to bear that in mind.
2. The new. Everything seemed revolutionary in the 60s, like they were inventing the answer to all of mankind's problems. This is a problem. Why? Because people tend to vest too much faith in 'experts.' That is what happens when you get rid of tradition. So it was with Rahner: everything he said was considered not only the truth, but final. And yet Rahner was as much a product and a victim of his own time. Like all lefties, he liked to pontificate about the future, and say stuff like "things can never go back to the way they were." How does he know that? But that maxim became axiomatic for liberals. We can't go back in time, to before multiculturalism, ecumenism, Darwinism, therefore, tradition is obsolete.
3. Live by the sword... Read his essay on Humane Vitae. Now apply everything he said about that unpopular encyclical to everything Pope Francis writes. Not nice is it? Just as Humane Vitae did not qualify for Rahner as definitive teaching because of X, Y, and Z, by the same measure feel free to ignore everything Pope Francis writes.
I will still continue to read Rahner, because I read everything and he was a genius. But, oh what a spoonful of humility liberals need to take to offset their bad case of "the history of right now."