 …let us say that a person decides to take and does take a certain drug, just in order to enjoy the euphoria he expects it to induce. Now suppose further that his taking the drug would have been made to happen in any case, by forces which were in fact inactive but which would have come into play if he had not on his own decided and acted as he did. Let us say that, unknown to himself, the person is addicted to the drug and would therefore have been driven irresistibly to take it if he had not freely gone about doing so. His dormant addiction guarantees that he could have avoided neither deciding to take nor taking the drug, but it plays no role in bringing about his decision or his act. As the actual sequence of events develops, everything happens as if he were not addicted at all. The addiction is clearly irrelevant in this case to the question of whether the person is morally responsible for taking the drug. (Frankfurt 1983: 322–3)