Final answer:
Freud's early theories were criticized for lacking empirical evidence and being unfalsifiable.
Step-by-step explanation:
A major criticism of Freud's early theories involves the fact that his theories lacked empirical evidence. Many of Freud's ideas, such as the existence of the id, ego, and superego, were not falsifiable and could not be tested through empirical observations. This lack of empirical evidence weakens the scientific validity of Freud's early theories.