different view; alternative theory; dissenting opinion
Used when presenting a viewpoint or theory that differs from the mainstream or from another stated position. Common in scholarly, legal, and news contexts.
There are several alternative theories about this case.
彼は会議で異説を唱えた。
He put forward a dissenting view at the meeting.
異説 is a dissenting or alternative theory that challenges the 定説, the currently accepted view.
Compound of 異 (different) and 説 (theory, opinion).