Making Clinical Ethical Decisions: Common Fallacies: 5. Argumentum ex Silentio
argumentum ex silentio is a fallacy appealing to ignorance as evidence to argue that something exists or doesn't exist. For example, the argument goes:" since we have no evidence that God doesn't exist, therefore he must exist". Or "because we have no knowledge of alien visitors to our earth from other planets, that would mean that alien visitors don't exist."
The state law allows the CEO of a hospital to permit organ donation of a patient was without friends who know him or family and who died without any sign that the patient had previously stated whether or not to allow his organs donated at death. An ethics committee met to decide the ethics of whether it was appropriate ethically for the hospital CEO to give permission for organ retrival on this patient. The ethical principle of beneficence would suggest that procurement of a vital organ from this deceased patient and transfer to a needy patient would be an ethical decision to consider. There are no other facts for the ethics committee to consider.
Yet, a troublesome factor can be introduced if the fallacy argumentum ex silentio is not rejected but used to make a decision. One can say, that even in death, patient autonomy while alive should be respected and since there is no information that the patient had accepted organ donation therefore one could argue that organ donation was unwanted. Or.. since there is no information that the patient rejected organ donation therefore one could argue that organ donation would have been acceptable to the patient. One could also argue one way or the other with regard to whether the patient had religious restrictions to transplant.
Avoiding the fallacy would have allowed the following logic: "we are ignorant regarding whether or not the patient had made any decision about organ donation, therefore there are no other facts for us to use to make a decision about whether or not it would be unethical for the CEO to decide to authorize organ procurement except the fact that donation would be considered as beneficence toward the recipient and thus on that basis the CEO's approval would be considered ethical."
Can you think of some other examples of use of this fallacy in making an argument? ..Maurice.