Alot of them use "idea" { sidbo } as the "ism" suffix, ...but I have some suggestions. I've never tried making lujvo before, mind you.
zoi . stidi .
libertarianism: advocating individual freedoms
"an epistemology of private freedom"
{ sivni zifre ve djuno } or { sivzifyveju'o }
communism: common ownership of means of production
"an epistomology of public industry"
{ gubni gundi ve djuno } or { gubgudveju'o }
.stidi.
and here's my reasoning.
zoi .ciksi.
an "-ism" in the sense of a person's approach to a subject, could be described as an idea { lo sidbo } or an abstraction { lo sucta }, or maybe a system of facts { lo ve djuno } or a methodology of facts { lo te saske }
...but functionally, I'd like if the word was an understanding of something { lo ve djuno }, and then it would make sense to translate
"What's your political stance on topic X"
"What's your political stance on the fact that X"
as
"What methodology do you employ to understand topic X"
"What methodology do you employ to know fact X"
a.k.a.
{ do djuno fi X fo ma }
{ do djuno fe X fo ma }
and then, you know, things like "libertarianism" or "communism" might be answers to that question. "I understand this issue (or know this fact) through the lens of..."
"I'm religiously marxist but fiscally libertarian"
{ mi gubgudju'o lo lijda .i kui mi sivzifyju'o lo djini }
. ciksi .
co'o