The phrase "a rationale for existence" is correct and usable in written English.
It can be used when discussing the reasoning or justification behind the existence of something, whether it be a concept, organization, or individual.
Example: "Philosophers often debate the rationale for existence, questioning why we are here and what purpose life serves."
Alternatives: "justification for being" or "reason for existence".
These simulations provide a rationale for the existence of two sets of niobium carbonitrides in commercial tubes of AISI 347.
We also find that homophily is strongly correlated with risk aversion, and we build on this evidence to derive a rationale for both the existence of homophily and the disappearance of in-group biases under endogenous matching.
In any case, one thing has been certain, that with the support of its founding sponsor American Express, the festival had the secure financial bedrock from which it could be nurtured into a yearly event sustained by more than its original rationale for existence.
Shiite militias would lose some of their rationale for existence, and Al Qaeda and Sunni insurgents could lose a useful foil.
The super-majority in the Gallup poll is exactly the outcome the Dixiecrats presciently warned would be the byproduct of desegregation, and took as their rationale for existence.
Where IRCs and attached video chats hew to explicit or implicit boundaries, realtime threads need their own rationale for existence to get much beyond the IM formula.
The cable news channels are already in turmoil because the cable and satellite big boys are reluctant (read: completely against as in Republicans and health care reform) to allow destabilization of their basic cable rationale for existence.
The existence of systemic banks provides a rationale for the central bank to act as lender of last resort for non-systemic banks in a larger range of their liquidity shortfalls.
It is not enough to cite the existence of the tax credit as a rationale for not increasing the minimum wage.
This belief in ultimate divine justice provides a rationale for theodicy, the reconciliation of God's goodness with the existence of evil in the world.
