Complex sentence: In many of his articles Kanner explicitly and clearly suggested that parental behavior can contribute to autism, but the renunciation of the idea by the person who originated it was seen as a decisive blow in any event.
Split into simpler sentences: In many of his articles Kanner explicitly and clearly suggested that parental behavior can contribute to autism. But the renunciation of the idea by the person who originated it was seen as a decisive blow in any event.