自分の主義に基づいて行動した。の英語

I acted up to my principles.

acting of your own free will

act on one's own judgment

Live up to one's principles.

adhere to one's opinion

to change one's principles―abandon one's principles―desert one's colours―turn one's coat

in an individualistic manner

That's opportunism, pure and simple.

That's opportunism pure and simple.

to do something at one's discretion

act up to one's opinions

to die a martyr to one's faith

I am playing it safe.

the condition of being greedy and selfish

act against one's will [conscience]

of or relating to or tending toward fundamentalism

He does everything at haphazard.

It is against my principles.

to hold to the ideas of nihilism

I will act up to my principles.

of an individual, to actively follow the doctrine that he or she professes to believe

refine on one's plan [theory]

a doctrine called primitivism

an attitude in life called rationalism

I tried to square my opinions with [to] the facts.

the act of following another person without having already established one's principles

as a matter of principle＝by principle

I will adhere to my principles―stick to my colours.

the exercise of one's judgment

He is an opportunist―a temporizer―a time-server.