The scientific expertise of doctors played a large part in the struggle to legalize and medicalize abortion as opposed to the “right to life” definition upon which the official Medical Association based its position. This article analyzes in particular how medicalization of the operation was linked to a reversal in the collective way of looking at medical ethics in the 1970’s. In accord with the previous definition, doctors were obliged to protect life at any price, even to the detriment of women’s lives. The fight in favour of abortion transformed what had been thought of as a crime into a public health issue falling under the responsibility of doctors. Nevertheless, two generations of doctors, having differing social stances and coming from radically different directions, disagreed on the question of the limits of medical expertise: for the first generation, the one involved in the French Family Planning Movement, the doctor must maintain a moral role allowing him to decide on the legitimacy of a request for abortion, while the younger doctors engaged in the struggle, on the extreme left and heavily invested in the student movement of 1968, campaigned in favour of granting the woman the complete freedom of her decision and reducing the doctor’s role to simply a technical one. The Veil Law enacts a compromise between the two conceptions, leaving the freedom of her choice to the woman though requiring she meet with a social worker to explain what she decides.