Synonyms for raison d'etre

The raison d'etre therefore for the book is convenience and arrangement.

Of course the raison d'etre of being here is the sulphur spring.

The raison d'etre of marriage is human happiness now and in the generations to follow.

The discussion of this proposal seems to make plain the raison d'etre for the existence of the Sentinel.

Moreover, we have the raison d'etre of the ghost: she had been a victim of the Chief Justice in Eyre.

The question was sufficiently important to demand an experimental solution; hence the raison d'etre of the present demonstration.

So my reader will perhaps understand the raison d'etre of the proverb, "The lawyers own England."