Final answer:
False, Casuists consider ethical decisions based on individual cases and context, thus, they do not believe that universal principles alone can solve complex bioethical cases.
Step-by-step explanation:
The statement 'Casuists argue that universal principles and rules are able to solve complex cases in bioethics' is False. Casuists generally believe that ethical decisions should be based on the specifics of individual cases rather than applying universal principles. They prioritize particular circumstances and context over general rules. In contrast, some other ethical frameworks, like deontological ethics, which could be associated with philosophers such as Immanuel Kant, argue for the importance of universal principles.