That would distinguish the hypotheses
Watching lots of black and white movies directly causes dreams to lose colour.
Knowing that all movies are black and white corrupts one’s memories about one’s dreams.
But it will not decide between
Watching lots of black and white movies directly corrupts one’s memories about one’s dreams.
That would distinguish the hypotheses
Watching lots of black and white movies directly causes dreams to lose colour.
Knowing that all movies are black and white corrupts one’s memories about one’s dreams.
But it will not decide between
Watching lots of black and white movies directly causes dreams to lose colour.
Watching lots of black and white movies directly corrupts one’s memories about one’s dreams.