He was quite philosophical about the sudden change in plans, saying it was an opportunity to try something new.

philosophical 是形容词，来自名词 philosophy（哲学）。在哲学语境中，它指"哲学的、哲学上的"；在日常用语中，常引申为"达观的、豁达的"，指像哲学家一样理性看待问题，保持冷静和超然的态度。