It seems to the use of the word ‘contrast’ in this thread, could be replaced by the word ‘variety’. Each hole having individuality--be it unique natural features or the nature of the site varying (like Cypress Point)...
...and/or designed individuality/variety: heavily bunkered/sparsely bunkered, severely undulating greens/flattish greens, a well defined-framed shot/blind shot over a hillock, low profile greens/pushed up greens, wide fairways/narrow fairway, cross-bunkers/bunker en echelon/diagonal hazards/central hazard, etc., etc.
I also believe, as Tom Simpson noted, having a ‘bad hole’ (quirky or less than ideal) or two adds to the variety and enjoyment of a golf course.
But within that variety IMO it is also important to have some uniting character, for example an architect’s style or aesthetic.
As far as the flow of a golf course, in my mind that is related to rhythm and its more difficult to put you finger on—although certainly design variety and architectural style has something to do with it. Probably the way the course fits into the site and uses the site has more to do with it.
There is no one formula: It could be the in and out of dunes, forest and sea at Cypress Point. It could be a tightly woven layout with continuity over very similar gentle ground like Chicago or GCGC. It could be a layout spread out over a massive site like Cape Breton with numerous very long walks from green to tee. The rhythm or flow has more to do with working with the natural features of the site.
The problem with Tillinghast’s quote is that some architects take it to an extreme and you get 18 holes having character beaten into them.