Complex sentence: He introduced this new discipline because he felt that the study of word-meaning could not be adequately met within the constraints of etymology or syntax, and that semasiology would properly show the development of word-meanings in a logical and historical sense.
Split into simpler sentences: He introduced this new discipline because he felt that the study of word-meaning could not be adequately met within the constraints of etymology or syntax. He felt that semasiology would properly show the development of word-meanings in a logical and historical sense.