The rare people who are solid

Sasha Chapin | Sasha’s Newsletter | Jan 12 2026

Congruence is a quality discussed by many psychologists—Carl Rogers popularized the word, saying that, among other things, it is a necessary trait in therapists. He defined it (roughly) as a state of unity between your experience, your self-concept, and your outward behavior. Which is to say: you aren’t pretending.

Deep congruence requires accepting all of the stuff of your life, every particle of feeling. If you are highly congruent, you disown none of your experience. None of it. You agree with what you’re doing with your time. You accept the stubborn approach of death, the arbitrariness of your fortune, your unimportance on the cosmic timescale, your potential importance for the local environment, the emotions of you and the people around you, the resources you’ve squandered. What stops congruence from occurring are layers of denial that are unpleasant to pass through. Although congruence is a source of endless happiness, the path there can be devastating. To paraphrase a cliche, you may have to finally give up on experiencing a better past.

How Writing Changes Mathematical Thought

John Pavlus | Quanta Magazine | Mar 25, 2026

“Mathematicians are doing something when they explore this realm that we experience as abstract,” Dunning said. “Ideas have developed in tandem with different ways of representing them in written form. This is where I find focusing on notation so useful — I see it as the way of grounding what mathematicians do in lived activity, in the physical world.”

More importantly, they’re not just a system for static representation. With them comes the algorithms we know for addition, multiplication, and so on — a way of calculating. We take that for granted: Schoolchildren learn how to carry digits and multiply large numbers together. But I think that brings into focus how the Hindu-Arabic numerals are an amazing technology. We are so used to a world where that technology has been widely available for so long, but it’s important to realize that historically, multiplying large numbers was a difficult thing to do — until you had a system that made it easy.

Leibniz wanted a much more algebraic, symbolic, notation-focused calculus. There’s this quote you see from him: “I dare say that this is the last effort of the human mind, and when this project shall have been carried out, all that men will have to do will be to be happy.” I mean, he sounds like an AI hype guy or something — this idea that our systems of writing can do the thinking for us. That’s really how Leibniz understood notation.