I'm just going to go ahead and hazard a guess that you don't actually have any understanding of history.
The idea that "science never started a war" is just downright false. Scientific progress has brought us the wonders of racially based discrimination, eugenics, social Darwinism, and so on.
I get the feeling you just have a dislike of organized religion and are spouting off whatever talking points you've seen mentioned with it.
Poor guess, every theory used to justify atrocities failed to pass the scientific method exactly because they were absurds that didn't reflect reality.
The problem is not religion in itself, the problem is belief without proof and blind obedience to authority and dogma.
Social Darwinism was a political theory which advocated for the removal of unfit or undesirable individuals from the gene pool as a measure of improving society through eugeny of future generations.
Not only it had no empirical basis, the cornerstone of the scientific method, to support it's supposed gains but the Nazis who implemented it arbitrarily choose which traits they considered superior which contradicts the very core of Darwinist Evolution that proposes the evolution of species happen by natural environmental pressure rather than arbitrary intelligent design.
Not only Nazi SD didn't accept the core of Darwin's theory that nature decides which trait offers more success in the gene pool but they jailed and butchered all scientist who disagreed with their narrative and burned all books which proposed more viable alternatives.
Whenever fanatics try to force their views against reality, they never find scientific proof to support their claims, they just murder or silence dissenters because reality will not conform to their desires.
By contrast, when the Bible or the Quran were written slavery was widely practiced and accepted amongst their respective societies and thus both books endorse it as something natural.
Hence, even though modern religious scholars denounce and condemn the practice the words are still there for fundamentalists like the ISIL or the Taliban to justify their atrocities.
It's not just religion which does that, communist China and the URSS worshipped no gods but preached adamantly that collective farming was the most productive way to feed a nation. They starved to death over 90 million people but never dared to question the wisdom of Mao and Stalin.
Philosophy is itself a science in which humans debate which values and standards are most ideal for a just and fair society, philosophers sustain their arguments not on dogmas from a single unquestionable source but from historical evidence and empirical observation of which practices and motivations bring most confort and security towards all human beings.
Even religious philosophers try to adapt their texts to the reality around them and the time they live in because they accept some of what their faith teaches no longer applies at face value now that evidence contradicts it.
The worst of humanity only surfaces when indoctrinated masses try to force their absurd beliefs against reality regardless if they believe in a god or not.
This is what is wrong with the templars, while some of them were open minded and desired to protect the innocent from magic abuse, the leadership indoctrinated the majority into the fanatic belief that their duty was to put down mages like animals because Andraste said magic must serve man.
Champions Of The Just shows exactly what the templar leadership does to dissenters amongst their ranks, they are round up in an isolated place and slaughtered by indoctrinated fanatics.
At least the leadership of the mages tried to be reasonable with a democratic vote and the College of Enchanters was at peace with oppositors at least until the templars gratuitously rejected the reformist efforts from the Chantry and launched a genocidal war against them.