Ens realissimum (n.) or the 'most real being' means not the most actual being but the one richest in what-content — lacking no positive determination.
5 definitions
Ens realissimum (n.) is the one single genuine ideal of which human reason is capable: the only case where a universal concept of one thing is thoroughly determined through itself.
The Ens realissimum (n.) is the original being from which all things, as defective copies (ectypa), take the matter of their possibility; however nearly they approach it, they always fall infinitely short.
The Ens realissimum (n.) grounds all things as a ground and not as a sum total: it is not an aggregate of derived beings, and our whole sensibility belongs to its consequences, not to it as an ingredient.
The Ens realissimum (n.) is a mere representation, yet it is first realized, then hypostatized, and finally personified — because the unity of experience seems to lie in a highest understanding.