"A strength to harm is perilous in the hand of an ambitious head"

This quote by Elizabeth I is a cautioning about the dangers of ambition and power. It suggests that when somebody has the strength to do damage, it can be harmful if they are ambitious. This is due to the fact that ambition can result in an individual wanting to utilize their power to acquire more power, or to control others. It is a reminder that power need to be used properly and with care. It is a cautioning to those in positions of power to be familiar with their own ambitions and to utilize their power for great, rather than for their own gain. It is also a suggestion to those who are not in positions of power to be aware of the potential dangers of ambition and to be cautious of those who have the strength to do harm.