Question

It may be a reflection on human nature, that such devices [checks and balances] should be necessary to control the abuses of government. . . . If men were angels, no government would be necessary.

This passage says that the government is necessary because
.

The passage states that checks and balances are needed to

Answer 1

1) because people are not perfect (not "angels") and need institutions to restrain their faults and govern their behavior.

2) to prevent abuses of power — i.e., to keep any one branch or person from becoming too powerful.