1 basic general rule
ADJ. basic, broad, central, fundamental, general the basic principles of car maintenance | cardinal, essential, key | universal | democratic, legal, market, political, scientific, theoretical
VERB + PRINCIPLE establish, formulate, lay down | apply | explain
PRINCIPLE + VERB apply This principle applies to all kinds of selling. | underlie sth, underpin sth the principles underlying Western philosophy
PREP. in ~ I agree with you in principle, but we'll need to discuss the details. | ~ behind She went on to explain the principles behind what she was doing.
2 rule for good behaviour
ADJ. high | guiding | Christian | moral He was a man of high moral principles.
VERB + PRINCIPLE betray, compromise I refuse to compromise my principles by eating meat. | adhere to, stick to She sticks to the principle that everyone should be treated equally.
PREP. against your ~s Eating meat was against her principles. | on ~ She's opposed to abortion on principle.
PHRASES a matter of principle They reject the proposal as a matter of principle. | a person of principle (= a person with high moral standards)