(a) Throughout the novella Death in Venice there are polarized dualities, one of which is that of culture. Whereas Gustav von Aschenbach has exhibited Germanic control, discipline, and intellect, when he travels to Venice, he is affected by the lure of the decadent city:
Yes, this was Venice, this was the fair frailty that fawned and that betrayed, half fairy-tale, half snare; the city in whose stagnating air the art of painting once put forth so lusty a growth, and where musicians were moved to accords so weirdly lulling and lascivious.
It is a city of decadence and deceit and license where Aschenbach feels "a dreamlike disaffection, a warping of the world into something alien [that] was about to take hold...." But, he has come to Venice because he has felt that his work has lacked a "playful fancy" and he hopes to attain a fresh look at things in Venice's "fairy tale location" and "most improbable of cities." Certainly, Venice is a venue for unbridled emotion in contrast to von Aschenbach's Germanic environment which emphasizes restraint and control.
(b) If "modernity" is defined as the present time, the "now" that breaks from the bonds of traditional beliefs and practices, the class-conscious Aschenbach who is so aware of his position and the discipline required of him, breaks from decorum. He moves from his perception of the beautiful Polish boy, symbolic of his repressed art, as a muse and young Phaedrus with whom he as Socrates holds internal dialogues--"Beauty is the path the man of feeling takes to the spiritual"--to a cosmetically enhanced foppish character, much like the elder man from whom he turned away earlier who declares to himself his passion for the boy. Initially the repressed artist, Aschenbach severs ties to tradition and form and becomes perverse in appearance and in desire.
(c) Venice is, indeed, a significant setting for Mann's novella as it has a long history of corruption and excessive passions. It is also an artistic environment with its beautiful, ancient architecture, frescoes, resplendent hand-blown glass and artistic tatting (lace-making). Beautiful and yet sinister with its dark gondolas and gondoliers who speak in incomprehensible dialects, stagnant canals, narrow, dark streets, bridges, and sultry climate, it is an appropriate backdrop for Ashenbach's perceptions of coffins and demons.
(d) There is always something of the artist in his art. As a young man, Thomas Mann was a friend of Paul Ehrenberg, a violinist and painter. Reportedly, Mann had homoerotic feelings toward Ehrenberg, an attraction that brought Mann difficulties and discomfiture. It is suspected that this attraction impeded his marriage to a young English woman in 1901.
Additionally, Mann's having been influenced by Nietzsche's proposed distinctions between the Dionysian and Apollonian "impulses in art" is evinced in his Death in Venice. With the Apollonian impulse leaning toward form, order, control, and rationality while the Dionysian leans toward disorder, spontaneity, emotional expression and intensity, and irrationality, the conflicts within Gustav von Aschenbach reflect the influence of these impulses.