Complex sentence: Smith considered "Sexual Preference" a useful study for its authors' challenge to established views about the causes of homosexuality, but found their account of homosexuality remote from real experience and was unconvinced by their conclusion that homosexuality itself has a biological basis.
Split into simpler sentences: Smith considered "Sexual Preference" a useful study for its authors' challenge to established views about the causes of homosexuality. However, he found their account of homosexuality remote from real experience and was unconvinced by their conclusion that homosexuality has a biological basis.