The phrase "invoke the principle" is correct and usable in written English.
It is generally used to mean either to refer to and appeal to a certain principle or to summon an authority or power, usually in order to enforce or strengthen an argument or opinion. For example: "The president invoked the principle of free speech to defend the controversial comments made by his administration."
I think it is appropriate to invoke the principle of self-defence and to target him".
The village of North Hills, which encompasses Deepdale, is considering a plan to invoke the principle of eminent domain to seize the facility.
"Islam is foreign to us and for that reason it cannot invoke the principle of religious freedom to the same degree as Christianity,"Hans-Thomas Tillschneider, an AfD politician from the state of Saxony-Anhalt, said to loud applause.
Despite numerous cases that invoke the principle of universal jurisdiction, Spain has secured only one conviction, that of an Argentine man named Adolfo Scilingo in 2005 for his involvement in "dirty war" killings of left-wing dissidents.
President Eisenhower, Bob Hope, Sidney Poitier, Charlie Rose and Mayor Bloomberg are among its members… The village of North Hills, which encompasses Deepdale, is considering a plan to invoke the principle of eminent domain to seize the facility.
Despite dozens of cases that invoke the principle of universal justice, Spain has secured only one conviction, that of Adolfo Scilingo, an Argentine who was convicted in 2005 for his involvement in killings during that nation's "dirty war" against leftist dissidents.
Really, a war can only be justified if you can invoke the principles of self-defence.
"In particular, no lawyer can invoke the principles of lawyer-client privilege to excuse participation, whether as principal or accessory, in offences against the Commonwealth".
Similarly, he has invoked the principle that he must protect his "compatriots"—meaning anybody he chooses to define as Russian wherever they are.
The first President Bush mobilized the world against Iraq by invoking the principle that nothing justifies one nation's invading another.
Ascensión Mendieta flew to Buenos Aires on her 88th birthday last year, where a judge has invoked the principle of universal justice to address Franco-era crimes.
