Knowing more has never meant more. Gender identity ideology is about more than twitter storms and using the right pronouns. In just ten years, laws, company policies, school and university curricula, sport, medical protocols, and the media have been reshaped to privilege self-declared gender identity over biological sex. People are being sacked and silenced for attempting to understand the consequences of redefining 'man' and 'woman'. While compassion for transgender lives is well-intentioned, it is stifling much-needed inquiry into the significance of our bodies, particularly with regard to women's rights, fairness in sport, same sex attraction and children's development. If we recommit to our liberal values of freedom of belief, freedom of speech and robust debate, we stand a chance of addressing what is at stake.