I love this "almost commutative" diagram Terry gives in a comment: pre-rigorous –––—> rigorous | ……………………………………….| v ……………………………………….v heuristic ––—> post-r

I love this "almost commutative" diagram Terry gives in a comment: pre-rigorous –––—> rigorous | ……………………………………….| v ……………………………………….v heuristic ––—> post-rigorous