Better yet how do you stop what happens in real life...
Which is that there are "Sciences" that are basically a load of nonsense and bullock such as Eugenics?
As far as I understand things, eugenics, while morally reprehensible, is not scientifically unsound. Are you thinking of race-biology and how people in that field manufactured evidence of racial superiority? The terms aren't interchangeable.
I thought Eugenics was dead?
We euthanized it for the betterment of mankind.
Here's what we do.
Hopeful political leaders sign up to the Government Academy (run by an independent commission with as many layers of arbitration and quality control as the state can afford). They get training in How To Govern, managing priorities, organising development, all that stuff. Side classes on political history, debating skills, pros and cons of different ideologies.
After they've graduated through all that, they get appointed to some random town or district for a year or so to prove their skills. They get a grade based on how various demographics have changed during their term (with allowances for things like legislation changes, disasters, and so on).
Candidates who can reduce commuting times, improve safety, grow businesses, and plan development effectively get higher grades than people who faff around. Approval rating is more or less a modifier, people who fuck everything up but are loved by the people get kicked out immediately, people who are generally hated but achieve a great deal get put on a PR course.
Eventually, the people with the best grades make it to the top, and nobody realises the real government is actually just the Commission.
Eh, I dunno. It seems like it'd be a little too easy for someone (or multiple someones) to go all Comrade Index Card on it, or for the various ideological groups represented to coordinate to paralyze the system with calls of biased treatment (or just not doing their jobs properly) to get what they want/crash the government with no survivors.
In my mind the main threat to this system wouldn't be corporatins or other private interests buying influence nor any particulate party/ideology "purifying" the teachings, but the "old buddies" cliques and thinking that would naturally form from such a system. We have enough of this as it is, we don't need more Camerons committing necrobeastiality with his good ol' pals.
The ideal relationship is that Peasants provide Kings with wealth in order for them to defend the peasants.
Isn't that what feudalism was, and didn't that suck?
Not on it's own, but yes, but for majorly other reasons.