Decide, determine, settle, rule, resolve mean to come or to cause to come to a conclusion.
Decide presupposes previous consideration of a matter causing doubt, wavering, debate, or controversy and implies the arriving at a more or less logical conclusion that brings doubt or debate to an end: the word may take as its subject the person or persons arriving at such a conclusion or the thing or things that bring them to the conclusion.
Determine (see also DISCOVER 2) may mean to set limits or bounds to: when it means basically to decide, this implication of definitely fixing something so that its identity, its character, its scope, its direction is clear and beyond doubt distinguishes it from decide; one decides to give a dinner party but determines the guests to be invited; a legislature decides that the state constitution should be revised and appoints a committee with power to determine what changes shall be made. In a slightly different sense determine implies the arrival at a conclusion that either is a fixed and unalterable purpose or intention or is the inevitable result, outcome, or end of what precedes.
Settle implies the arrival at a conclusion, often a mental or logical conclusion but sometimes a termination for which no individual is responsible, that brings to an end all doubt, all wavering, all dispute.
Rule (see also GOVERN) implies a decision or determination by authority, especially by the authority of the court.
Resolve implies an expressed or clear decision or determination to do or refrain from doing something.