We can’t ask babies what they’re feeling, but ingenious new methods are shedding light on the origins of subjective awareness As recently as the 1980s, many infants were operated on without anaesthesia – a practice that would be unthinkable today. Recounting this history in his book The Edge of Sentience (2024), the philosopher Jonathan Birch notes his surprise at the moral arrogance of anaesthesiologists of the time. What could have justified this practice?