The proof that scientists are slaves to their time is evident in the presence of morality within science.
If science cannot establish moral truths (whatever this means (ask the opponent for a definition)), it means that the morality was imposed from the outside and accepted, coercively or not, within the community.
The science of today is not the same as the science of yesterday, (whatever this means).
Science is not science.
Science means whatever you want it to mean.
QED.

What happens if you prove this false?