Spinoza's Ethics: II.P11: Essence of a Human Mind

Spinoza's scholium reveals his awareness that this section is difficult to understand. In the prior proposition, he addresses the essence of a human as modal and not substantial. Given his earlier propositions, this modal essence manifests equally within attributes of existing and thinking. The modal manifestations are clear: a human body and a human mind. Insofar as these modes don't exist, they are simply formal or virtual (in my words). But existence changes all of that. The essence of an existing human body is (yet to be discussed but will ultimately be given) conatus. The essence of an existing human mind is a singular idea of an existing singular thing that is both prior by nature and adequate. Both existing modes are connected together within their respective attributes by the power of God's expressiveness. Conatus is a human body's modal expressiveness, while adequacy is a human mind's modal expressiveness. The power of the human mind's expressiveness can be weakened by inadequate ideas. This is briefly highlighted at the end of this corollary.  

Primum quod actuale mentis humanæ esse constituit, nihil aliud est quam idea rei alicujus singularis actu existentis.

Translated as,

The first thing which constitutes the actual essence of a human mind is nothing other than the idea of a singular thing in actual existence.

DEMONSTRATIO: Essentia hominis (per corollarium præcedentis propositionis) a certis Dei attributorum modis constituitur nempe (per axioma 2 hujus) a modis cogitandi quorum omnium (per axioma 3 hujus) idea natura prior est et ea data reliqui modi (quibus scilicet idea natura prior est) in eodem debent esse individuo (per axioma 3 hujus). Atque adeo idea primum est quod humanæ mentis esse constituit. At non idea rei non existentis. Nam tum (per corollarium propositionis 8 hujus) ipsa idea non potest dici existere; erit ergo idea rei actu existentis. At non rei infinitæ. Res namque infinita (per propositiones 21 et 22 partis I) debet semper necessario existere; atqui hoc (per axioma 1 hujus) est absurdum; ergo primum quod esse humanæ mentis actuale constituit, est idea rei singularis actu existentis. Q.E.D.

Translated as,

The essence of a human (by IIP10C) is constituted by certain modes of attributes of God, indeed (by IIA2) by modes of thinking whose idea of everything (by IIA3) is prior by nature and, [the idea] having been given, the remaining modes (by which of course the idea is prior by nature) must be in the same individual (by IIA3). And to such a degree the idea at first is what constitutes the essence of a human mind. But not the idea of a thing not existing. For then (by IIP8C) the idea itself is not able to be said to exist; it will therefore be the idea of a thing existing in actuality. But not of an infinite thing. For an infinite thing (by IP21 and IP22) ought to exist by necessity. And this (by IIA1) is absurd. Therefore at first which constitutes the actual essence of a human mind is the idea of a singular thing in actual existence.

COROLLARIUM: Hinc sequitur mentem humanam partem esse infiniti intellectus Dei ac proinde cum dicimus mentem humanam hoc vel illud percipere, nihil aliud dicimus quam quod Deus non quatenus infinitus est sed quatenus per naturam humanæ mentis explicatur sive quatenus humanæ mentis essentiam constituit, hanc vel illam habet ideam et cum dicimus Deum hanc vel illam ideam habere non tantum quatenus naturam humanæ mentis constituit sed quatenus simul cum mente humana alterius rei etiam habet ideam, tum dicimus mentem humanam rem ex parte sive inadæquate percipere.

Translated as,

From here it follows that a human mind is part of the infinite intellect of God and next when we say that a human mind perceives this or that, we say nothing other than that God, not insofar as it is infinite, but insofar as it is explained by the nature of the human mind or insofar as it constitutes the essence of the human mind, has this or that idea and when we say that God has this or that idea not so much insofar as it constitutes the nature of the human mind but insofar as at the same time it even has the idea of another thing with a human mind, then we say that a human mind perceives a thing partially or inadequately.

SCHOLIUM: Hic sine dubio lectores hærebunt multaque comminiscentur quæ moram injiciant et hac de causa ipsos rogo ut lento gradu mecum pergant nec de his judicium ferant donec omnia perlegerint.

Translated as,

Here without a doubt readers will be stuck and confuse many things which inject a delay and for this reason I ask these same [readers] that they proceed with me by a slow step and not make a judgment concerning these things as long as they are reading everything to the end.