Complex sentence: He believed the exhibiting of the Collection educated the public about the creativity and humanity of those with mental illness, and he showed work from as early as 1947 in group shows of'psychiatric art'.
Split into simpler sentences: He believed the exhibiting of the Collection educated the public about the creativity and humanity of those with mental illness. He showed work as early as 1947 in group shows of, to use a term from the time,'psychiatric art'.