The strongest is never strong enough to be always the master unless he transforms strength into right and obedience into duty.

Children totally accept — and crave — family rules. “In our family we have a rule for X” is the only excuse a parent needs for setting a family policy. In fact， “I have a rule for X” is the only excuse you need for your own personal policies.

The concept of inflation suggests that the universe underwent a period of extremely rapid expansion shortly after the Big Bang.