Can Consent Be Withdrawn After It Has Been Given?

Consent is not a one-off transfer of decision-making authority. It permits another person, under particular conditions, to do something they would otherwise lack permission to do. The Stanford Encyclopedia of Philosophy's discussion of informed consent notes that when a decisionally capable adult clearly changes their mind, the new refusal matters even after repeated earlier consent. If consent could never be withdrawn, its protection of autonomy would shrink to a single signature.

Suppose you give a friend a private photograph to edit and agree that they may post it later. Before it is posted, you change your mind. Withdrawing consent means the friend no longer has permission to publish it. What changes is the normative status of a future action, not the past: withdrawal cannot undo the fact that the friend has already seen the photograph.

Nor does withdrawal automatically erase every consequence. If the other person has incurred costs under a reasonable arrangement, questions of payment or compensation may remain. If consent is embedded in a contract, the legitimacy and enforceability of its exit terms also matter. Consent and promise must be kept distinct: consent mainly removes a prohibition on another person's act, while a promise may place an obligation on oneself.

My view is that consent should in principle remain withdrawable before the authorised act occurs. Withdrawal need not operate retrospectively, and it does not cancel responsibilities created on separate grounds. Respecting a change of mind does not mean choices are costless; it means recognising that the person remains an authority over what is still to happen.

https://plato.stanford.edu/entries/informed-consent/