Definition of "aloneness"

Suddenly, [...] he saw all this as romantic — the last legionary, his aloneness, the lost cause really lost — and instinctively he pulled in his paunch, stroked down his hair to cover the naked part of the scalp, and wiped the sweat off his cheeks.

1959, Anthony Burgess, Beds in the East (The Malayan Trilogy), published 1972, page 425