Temple of Athena, Paestum, c. 500 BCE
To me this is one of the most satisfying works of art in the world. I can only think of it as we have it now, a ruin; its spare, bare qualities and open roof emphasize and at the same time diminish its immense physicality and weight. The rhythmic nature of the peripteral colonnade sets a standard. It presents Doric strength with the most compelling and inviting qualities. The textures and colors, which can only hover uncertainly about any reproduction, contribute much here.
When this slide shows up in class I usually ask students to think of it as a kind of self-portrait of the Classical mind. Its harmonies exquisitely call to mind (mind!) a sense of rational inquiry combined with visual pleasure. Idealism is often too far removed or abstract to be felt as a physical sensation, and here the combination of the two is unearthly. With my students, I usually tend to identify the Doric by quick reference to the capital - Doric echoes in our neighborhoods are usually just that - but I always turn back to this temple to remind me of the Order's particular eloquence.
I don't know how accurate I am when I talk about this as a self-portrait of the Classical mind - might one say the same of anything in the Classical canon? - but as a heuristic I believe it helps get at something that was getting at the Greeks. The beauty we locate in the harmonies of proportion is apprehended one way by the architect who has measured and arranged, another to those of us who just look, but in each case a sense of the parts relating to other parts and of how they relate to the whole helps us to appreciate and makes us glad.